Light-emitting element, light-emitting element unit, electronic device, light-emitting device, sensing device, and communication device

Abstract

The light-emitting element according to the present disclosure is provided with: a laminated structure 20 in which a first compound semiconductor layer 21, an activation layer 23, and a second compound semiconductor layer 22 are laminated; a first light reflection layer 41 formed on a first-surface side of the first compound semiconductor layer 21; a second light reflection layer 42 formed on a second-surface side of the second compound semiconductor layer 22; a first electrode 31 electrically connected to the first compound semiconductor layer 21; and a second electrode 32 electrically connected to the second compound semiconductor layer 22. The light-emitting element is provided with a current constriction region 52 for controlling inflow of current to the activation layer 23. When an axis which is in the thickness direction of the laminated structure 20 and which passes through the center of a current injection region 51 surrounded by the current constriction region 52 is defined as Z axis, a direction orthogonal to Z axis is defined as an X direction, the direction orthogonal to the X direction and Z axis is defined as a Y direction, the current injection region 51 has a elongated planar shape in which the longitudinal direction extends in the Y direction.

Description

[Technical Field]

[0001] The present disclosure relates to a light-emitting element, more specifically, a light-emitting element formed of a vertical cavity surface-emitting laser (VCSEL), a light-emitting element unit including such a light-emitting element, an electronic device, a light-emitting device, a sensing device, and a communication device. [Background technology]

[0002] For example, in a light-emitting device comprising a surface-emitting laser element disclosed in WO2018 / 083877A1, laser oscillation occurs by resonating laser light between two optical reflection layers (Distributed Bragg Reflector layer, DBR layer). In a surface-emitting laser element having a stacked structure in which an n-type compound semiconductor layer (first compound semiconductor layer), an active layer (light-emitting layer) made of compound semiconductors, and a p-type compound semiconductor layer (second compound semiconductor layer) are stacked, a second electrode made of a transparent conductive material is formed on the p-type compound semiconductor layer, and a second optical reflection layer is formed on the second electrode. Furthermore, a first optical reflection layer and a first electrode are formed on the n-type compound semiconductor layer (or on the exposed surface of the substrate if the n-type compound semiconductor layer is formed on a conductive substrate). In this specification, the term "upper" may refer to a direction away from the active layer, the term "lower" may refer to a direction toward the active layer, and the terms "convex" and "concave" may refer to the active layer. The orthogonal projection image is an orthogonal projection image onto a laminated structure (described later).

[0003] Light-emitting elements often require the emitted laser light to have high linearity, in other words, a narrow emission angle (radiation angle). A narrower emission angle reduces the proportion of laser light that leaks out when the laser light is coupled to another optical system, thereby increasing coupling efficiency. Furthermore, the optical system used can be made smaller and simpler, and it becomes easier to irradiate distant objects without an external optical system such as a lens. Furthermore, when the emitted laser light is focused, the focal depth is deep, which can relax requirements for the positional accuracy of various components. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2018 / 083877A1 Summary of the Invention [Problem to be solved by the invention]

[0005] However, to obtain a light-emitting device with high linearity, it is necessary to effectively expand the optical and electrical confinement region. In the technology disclosed in WO2018 / 083877A1, the first light-reflecting layer has a concave mirror structure, which allows a light field with reduced lateral spread to be positioned within the device region (described below), thereby achieving laser oscillation. Confining light in a narrower region achieves low power consumption. However, the light confinement region is wide. Therefore, the emission angle is large, and the FFP (Far Field Pattern) is, for example, several degrees, which may not satisfy the requirement for a narrow emission angle. Furthermore, if the light emitted from the light-emitting device itself has a certain shape (e.g., a figure, pattern), the configuration and structure of electronic devices equipped with such light-emitting devices can be simplified.

[0006] Therefore, a first object of the present disclosure is to provide a light-emitting element with a narrow emission angle (radiation angle) and a light-emitting element unit including such a light-emitting element. A second object of the present disclosure is to provide a light-emitting element in which the emitted light itself has a certain shape. Further objects of the present disclosure are to provide electronic devices, light-emitting devices, sensing devices, and communication devices. [Means for solving the problem]

[0007] In order to achieve the first or second object described above, a light-emitting device according to a first or second aspect of the present disclosure comprises: a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light-reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with A current confinement region is provided to control the flow of current into the active layer.

[0008] In the light-emitting device according to the first aspect of the present disclosure, when the thickness-wise axis of the stacked structure passing through the center of the current injection region surrounded by the current constriction region is defined as the Z-axis, the direction perpendicular to the Z-axis is defined as the X-direction, and the direction perpendicular to the X-direction and the Z-axis is defined as the Y-direction, the current injection region has an elongated planar shape with its longitudinal direction extending in the Y-direction.

[0009] Furthermore, in the light-emitting element according to the second aspect of the present disclosure, the planar shape of the current injection region surrounded by the current confinement region is composed of at least one shape selected from the group consisting of a ring, a ring with a portion cut out, a shape surrounded by curves, a shape surrounded by multiple line segments, and a shape surrounded by curves and line segments.

[0010] In order to achieve the first object, the light-emitting element unit of the present disclosure is a light-emitting element unit including a plurality of light-emitting elements, Each light-emitting element is composed of a light-emitting element according to the first aspect of the present disclosure; The plurality of light emitting elements are arranged at intervals in the X direction.

[0011] The electronic device or light emitting device of the present disclosure includes the light emitting element according to the first or second aspect of the present disclosure, or the light emitting element unit of the present disclosure.

[0012] The sensing device of the present disclosure comprises: A light emitting device including the light emitting element according to the first or second aspect of the present disclosure, or the light emitting element unit according to the present disclosure, and a light receiving device that receives the light emitted from the light emitting device; It has.

[0013] The communication device of the present disclosure includes: A light emitting device including a plurality of types of light emitting elements according to the second aspect of the present disclosure; and a light receiving device that receives the light emitted from the light emitting device; It has. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic partial end view of the light emitting device of Example 1. FIG. [Figure 2] Figure 2(A) is a diagram showing a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode that constitute the light-emitting element of Example 1, and Figures 2(B) and 2(C) are schematic partial end views of the light-emitting element of Example 1 along arrows BB and CC in Figure 2(A). [Figure 3] FIGS. 3A, 3B, and 3C are essentially the same as FIGS. 2A, 2B, and 2C, but with various parameters added. [Figure 4] FIG. 4 is a schematic partial end view of a first modified example of the light emitting device of the first embodiment. [Figure 5] FIG. 5 is a schematic partial end view of a modified example 2 of the light emitting device of the first embodiment. [Figure 6] FIG. 6 is a schematic partial end view of a third modified example of the light emitting device of the first embodiment. [Figure 7] FIG. 7 is a schematic partial end view of a fourth modified example of the light emitting device of the first embodiment. [Figure 8] FIG. 8 is a diagram showing a schematic arrangement of a current injection region, a current confinement region, and a second electrode that constitute the light emitting device of Example 2. In FIG. [Figure 9]FIG. 9 is a diagram schematically showing the arrangement of the current injection region, the current confinement region, and the second electrode that constitute the light emitting device of Example 2. In FIG. [Figure 10] (A) of Figure 10 is a diagram showing a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode that constitute variant-1 of the light-emitting element of Example 2, and (B) and (C) of Figure 10 are schematic partial end views of variant-1 of the light-emitting element of Example 2 along arrows BB and CC in (A) of Figure 10. [Figure 11] (A) of Figure 11 is a diagram showing a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode that constitute variant-2 of the light-emitting element of Example 2, and (B) of Figure 11 is a schematic partial end view of variant-2 of the light-emitting element of Example 2 along arrow BB in (A) of Figure 11. [Figure 12] FIG. 12 is a schematic partial end view of the light emitting device of Example 3. As shown in FIG. [Figure 13] 13A and 13B are diagrams schematically showing the arrangement of a current injection region, a current confinement region, and a second electrode in a light-emitting element constituting the light-emitting element unit of Example 4. FIG. [Figure 14] FIG. 14 is a schematic partial end view of the light-emitting element unit of Example 4. As shown in FIG. [Figure 15] FIG. 15 is a schematic partial end view of a first modified example of the light-emitting element unit of the fourth embodiment. [Figure 16] FIG. 16 is a schematic partial end view of the light-emitting device of Example 5. As shown in FIG. [Figure 17] 17A, 17B, 17C, and 17D are diagrams schematically showing the arrangement of the current injection region, the current confinement region, and the second electrode that constitute the light-emitting device of Example 5. FIG. [Figure 18] (A) of Figure 18 is a diagram showing a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode that constitute the light-emitting element of Example 5, and (B) of Figure 18 is a diagram showing a schematic diagram of the arrangement of the current injection region and current confinement region that constitute the light-emitting element of Example 5. [Figure 19]19A, 19B, 19C, 19D, and 19E are diagrams schematically showing the planar shape of the current injection region that constitutes the light emitting device of Example 5. FIG. [Figure 20] FIG. 20 is a schematic partial end view of the light-emitting device of Example 7. As shown in FIG. [Figure 21] 21A and 21B are schematic partial end views of a laminated structure and the like for explaining a manufacturing method of the light emitting device of Example 1. FIG. [Figure 22] 22 is a schematic partial end view of the laminated structure and the like for explaining the manufacturing method of the light emitting element of Example 1, following FIG. 21B. [Figure 23] 23 is a schematic partial end view of the laminated structure and the like for explaining the method for manufacturing the light emitting element of Example 1, following FIG. 22. In FIG. [Figure 24] 24A, 24B, and 24C are schematic partial end views of the first compound semiconductor layer and the like for explaining the method for manufacturing the light-emitting element of Example 1, following FIG. [Figure 25] 25A, 25B, and 25C are schematic partial end views of a laminated structure and the like for explaining a method for manufacturing a light-emitting element according to Example 3. FIG. [Figure 26] 26A, 26B, and 26C are schematic partial end views of a laminated structure and the like for explaining a method for manufacturing a light-emitting element according to Example 3. FIG. [Figure 27] 27A and 27B are schematic partial end views of the laminated structure and the like for explaining the manufacturing method of the light-emitting element of Example 3, following FIG. 25C. [Figure 28] FIG. 28 is a schematic partial cross-sectional view of the light-emitting device of Example 7, and a diagram in which two longitudinal modes, longitudinal mode A and longitudinal mode B, are superimposed. [Figure 29] 29A and 29B are conceptual diagrams that schematically show longitudinal modes that exist in the gain spectrum determined by the active layer. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present disclosure will be described below based on examples with reference to the drawings, but the present disclosure is not limited to the examples, and various numerical values ​​and materials in the examples are merely examples. The description will be made in the following order. 1. General Description of the Light-Emitting Device According to the First and Second Aspects of the Present Disclosure, the Light-Emitting Device Unit of the Present Disclosure, etc. 2. Example 1 (Light-emitting device according to the first aspect of the present disclosure) 3. Example 2 (Modification of Example 1) 4. Example 3 (Modification of Examples 1 and 2) 5. Example 4 (light-emitting element unit of the present disclosure) 6. Example 5 (Light-emitting device according to the second aspect of the present disclosure) 7. Example 6 (Modification of Examples 1 to 5) 8. Example 7 (Modification of Examples 1 to 6) 9. Example 8 (Modification of Example 7) 10. Example 9 (another variation of Example 7) 11. Example 10 (Application of the light-emitting element according to the first and second aspects of the present disclosure and the light-emitting element unit according to the present disclosure) 12. Example 11 (Application of the light-emitting element according to the first and second aspects of the present disclosure and the light-emitting element unit according to the present disclosure) 13. Example 12 (Application of the light-emitting element according to the first and second aspects of the present disclosure and the light-emitting element unit according to the present disclosure) 14.Other

[0016] <General Description of Light-Emitting Devices According to the First and Second Aspects of the Present Disclosure, Light-Emitting Device Units of the Present Disclosure, and the Like> In the light-emitting device according to the first aspect of the present disclosure, the width of the current injection region along the Y direction is L max-Y , the width along the X direction is L min-X When L max-Y / L min-X ≧3 Preferably, L max-Y / L min-X ≧20 The width L of the current injection region along the Y direction can be max-Y , width L along the X directionmin-X If there is any variation, fluctuation or change in the width L min-X When changing the width, the average width is L max-Y ,L min-X The same applies to the following explanation.

[0017] In the light-emitting device according to the first aspect of the present disclosure, including the preferred embodiment described above, the first light-reflecting layer may have a convex shape extending away from the active layer, and the second light-reflecting layer may have a flat shape. In this case, the cavity length L along the Z axis may be OR Including, but not limited to, 1×10 -5 m≦L OR ≦5×10 -5 m Examples include:

[0018] Here, when the second surface of the first compound semiconductor layer is used as a reference, a first portion of the base surface (described later) on which the first light reflecting layer is formed has an upwardly convex shape. The portion of the base surface outside the first portion is called the second portion, and when the second surface of the first compound semiconductor layer is used as a reference, the second portion is either flat or recessed toward the second surface. The second portion of the base surface is sometimes called a peripheral region. An extension of the first light reflecting layer may be formed on the second portion of the base surface, or the first light reflecting layer may not be formed on the second portion.

[0019] The shape (figure) drawn by the first or second portion of the base surface when the first or second portion of the base surface is cut along an XZ imaginary plane can be a portion of a circle, a portion of a parabola, a portion of a sine curve, a portion of an ellipse, or a portion of a catenary curve. The shape (figure) may not strictly be a portion of a circle, a portion of a parabola, a portion of a sine curve, a portion of an ellipse, or a portion of a catenary curve. In other words, the phrase "a shape that is a portion of a circle, a portion of a parabola, a portion of a sine curve, a portion of an ellipse, or a portion of a catenary curve" encompasses cases where the shape is approximately a portion of a circle, a portion of a parabola, a portion of a sine curve, a portion of an ellipse, or a portion of a catenary curve. Some of these curves may be replaced with line segments. The shape (figure) drawn by the base surface can be determined by measuring the shape of the base surface with a measuring instrument and analyzing the obtained data using the least squares method.

[0020] Furthermore, the shape (figure) of the apex when the first portion of the base surface is cut by the YZ imaginary plane can be configured to be a line segment and a part of a circle, a part of a parabola, a part of a sine curve, a part of an ellipse, or a part of a catenary curve extending from one end and the other end of the line segment. The line segment when the flat second portion of the base surface is cut by the YZ imaginary plane and the line segment portion of the shape (figure) of the apex when the first portion of the base surface is cut by the YZ imaginary plane can be configured to be parallel.

[0021] The radius of curvature R1 at the center of the shape drawn by the convex part when the first part of the base surface is cut by the XZ virtual plane is 1.5×10 -5 m≦R1≦1×10 -3 m Preferably, 3×10 -5 m≦R1≦1.5×10 -4 m It is desirable to satisfy the following.

[0022] The second portion of the base surface may be flat or may be concave toward the second surface of the first compound semiconductor layer. In the latter case, the radius of curvature R2 of the central portion of the second portion of the base surface when cut along the XZ virtual plane is 1×10 -6 m or more, preferably 3×10 -6 m or more, more preferably 5×10 -6 m or more.

[0023] Here, it is desirable that it is differentiable from the first portion to the second portion. That is, when the base surface is represented by z = f(x, y), the derivative value on the base surface is ∂z / ∂x = [∂f(x, y) / ∂x] y ∂z / ∂y = [∂f(x, y) / ∂y] x and can be obtained. "Smooth" is a term in analysis. For example, if a real variable function f(x) is differentiable at a < x < b and f'(x) is continuous, it can be said to be continuously differentiable in a catchphrase, and it can also be expressed as smooth. And the portion where an inflection point exists on the base surface extending from the first portion to the second portion is the boundary between the first portion and the second portion.

[0024] [From the peripheral portion to the central portion of the first portion / second portion], the shape is (A) [Convex upward shape / Concave downward shape] (B) [Convex upward shape / Continues to a line segment from the concave downward shape] (C) [Convex upward shape / Continues from the convex upward shape to the concave downward shape] (D) [Convex upward shape / Continues from the convex upward shape to the concave downward shape and then to a line segment] (E) [Convex upward shape / Continues from a line segment to the concave downward shape] (F) [Convex upward shape / Continues from a line segment to the concave downward shape and then to a line segment] There are cases like this. In the light-emitting element, there may be a case where the base surface terminates at the central portion of the second portion.

[0025] Furthermore, in the light-emitting element according to the first aspect of the present disclosure, which includes the preferred embodiments described above, the planar shape of the first light-reflecting layer can be a shape that is similar (an approximate shape) to the planar shape of the current injection region.

[0026] Furthermore, in the light-emitting device according to the first aspect of the present disclosure including the preferred embodiments described above, the light emission angle θ Y The angle of emergence of light on the XZ virtual plane can be set to θ X The FFP of the light emitting element is calculated, and the output angle θ is calculated by a well-known method from the FFP on the YZ virtual plane when the light emitting element is assumed to be cut on the YZ virtual plane. Y The output angle θ can be calculated by a well-known method from the FFP on the XZ virtual plane when the light emitting element is assumed to be cut on the XZ virtual plane. X The output angle is the angle at which the light intensity is the full width at half maximum of the maximum light intensity in the light beam distribution of the FFP.

[0027] Furthermore, in the light-emitting device according to the first aspect of the present disclosure, including the preferred embodiment described above, the planar shape of the current injection region may be an oval. Here, the oval shape is a shape formed by two parallel line segments, a semicircle connecting one end of the two line segments, and a semicircle connecting the other end of the two line segments. The two line segments may also be replaced by two curved lines.

[0028] Alternatively, in the light-emitting device according to the first aspect of the present disclosure, including the preferred embodiment described above, the planar shape of the current injection region may be rectangular. In such a configuration, a side surface of the current injection region including a side parallel to the X direction may be in contact with the current confinement region, an end surface of the current injection region including a side parallel to the X direction may be in contact with, for example, the atmosphere, or an end surface of the current injection region including a side parallel to the X direction may be in contact with a layer (a laminate film) in which first dielectric layers and second dielectric layers are alternately arranged in the Y direction. The outer surface of this laminate film may be in contact with the current confinement region or, for example, with the atmosphere. Furthermore, in these configurations, the side of the current injection region parallel to the Y direction may be configured as a line segment or a curve.

[0029] In the light-emitting device according to the second aspect of the present disclosure, the planar shape of the current injection region may be configured to be a letter or a graphic.

[0030] In the light-emitting element unit of the present disclosure, the width of the current injection region in each light-emitting element along the Y direction is L max-Y , the width along the X direction is L min-X When L max-Y / L min-X ≧3 Preferably, L max-Y / L min-X ≧20 Satisfied, The arrangement pitch of the multiple light emitting elements along the X direction is P X When P X / L min-X ≧1.5 Preferably, P X / L min-X ≧5 It is possible to make it a form that satisfies the above.

[0031] In the light-emitting element unit of the present disclosure including the above-described preferred embodiments, In the entire light-emitting element unit, The light emission angle θ on the YZ virtual plane Y ' is less than 2 degrees, The light emission angle θ on the XZ virtual plane X ' may be in the form of 0.1 degrees or less.

[0032] Furthermore, in the light-emitting element unit of the present disclosure including the preferred embodiments described above, the first electrode is common to the plurality of light-emitting elements; The second electrode may be provided individually for each light-emitting element, or may be the first electrode is common to the plurality of light-emitting elements; The second electrode may be common to a plurality of light-emitting elements.

[0033] Furthermore, in the light-emitting device according to the present disclosure, including the preferred embodiments and configurations described above, the second electrode may be configured to have a plurality of grooves extending in one direction (e.g., a first direction) to control the polarization state of light emitted from the light-emitting device. Specifically, the plurality of grooves extending in the first direction are contained in a virtual plane (an XY virtual plane) perpendicular to the thickness direction of the second electrode. When the groove formation pitch P0 is significantly smaller than the wavelength λ0 of the incident light, light vibrating in a plane parallel to the extension direction of the grooves (the first direction) is selectively reflected and absorbed by the grooves. Here, the distance between the line portions of the grooves (the distance between the space portions along the second direction) is defined as the groove formation pitch P0. In this case, the light (electromagnetic wave) reaching the grooves contains both vertically polarized and horizontally polarized components, but the electromagnetic wave passing through the grooves becomes linearly polarized light with a predominantly vertically polarized component. Here, when considering the visible light wavelength band, the groove formation pitch P0 is the effective wavelength λ of the light (electromagnetic wave) incident on the groove. eff If the refractive index is significantly smaller than n, the polarization component polarized in a plane parallel to the first direction is reflected or absorbed by the surface of the groove. On the other hand, when light having a polarization component polarized in a plane parallel to the second direction is incident on the groove, the electric field (light) propagating on the surface of the groove is transmitted (emitted) with the same wavelength and polarization direction as the incident wavelength from the back surface of the groove. Here, the average refractive index calculated based on the material present in the space portion is nave When this is done, the effective wavelength λ eff is (λ0 / n ave ) is expressed as the average refractive index n ave is the sum of the product of the refractive index and volume of the material present in the space and divided by the volume of the space. When the wavelength λ0 is constant, n ave The smaller the value of , the greater the effective wavelength λ eff The value of n becomes larger, and therefore the value of the forming pitch P0 can be increased. ave The larger the value of , the lower the light transmittance in the grooves and the lower the extinction ratio.

[0034] In the light-emitting devices according to the first and second aspects of the present disclosure (hereinafter referred to as "light-emitting devices, etc. according to the present disclosure") including the preferred forms and configurations described above, the laminated structure can be configured to be made of at least one material selected from the group consisting of GaN-based compound semiconductors, InP-based compound semiconductors, and GaAs-based compound semiconductors. Specifically, the laminated structure can be configured to be made of at least one material selected from the group consisting of GaN-based compound semiconductors, InP-based compound semiconductors, and GaAs-based compound semiconductors. (a) Structure made of GaN-based compound semiconductors (b) Structure made of InP-based compound semiconductors (c) Structure made of GaAs-based compound semiconductors (d) Composition consisting of GaN-based compound semiconductors and InP-based compound semiconductors (e) Composition consisting of GaN-based compound semiconductors and GaAs-based compound semiconductors (f) Composition consisting of InP-based compound semiconductors and GaAs-based compound semiconductors (g) Composition consisting of GaN-based compound semiconductors, InP-based compound semiconductors, and GaAs-based compound semiconductors Examples include:

[0035] In the light-emitting device and the like of the present disclosure, the thermal conductivity of the laminated structure can be configured to be higher than that of the first light-reflecting layer. The thermal conductivity of the dielectric material that constitutes the first light-reflecting layer is generally about 10 Watts / (m·K) or less. On the other hand, the thermal conductivity of the GaN-based compound semiconductor that constitutes the laminated structure is about 50 Watts / (m·K) to 100 Watts / (m·K).

[0036] In the light-emitting device etc. of the present disclosure, when various compound semiconductor layers (including a compound semiconductor substrate) are present between the active layer and the first light-reflecting layer, it is preferable that the materials constituting these various compound semiconductor layers (including a compound semiconductor substrate) do not have a refractive index modulation of 10% or more (no refractive index difference of 10% or more based on the average refractive index of the laminated structure), which makes it possible to suppress the occurrence of disturbances in the optical field within the resonator.

[0037] The light-emitting element and the like of the present disclosure can be used to form a surface-emitting laser element (vertical cavity laser, VCSEL) that emits laser light through a first light-reflecting layer, or a surface-emitting laser element that emits laser light through a second light-reflecting layer. In some cases, the substrate for manufacturing the light-emitting element (described later) may be removed.

[0038] In the light-emitting device etc. of the present disclosure, the stacked structure can be specifically configured to be made of, for example, an AlInGaN-based compound semiconductor, as described above. More specific examples of AlInGaN-based compound semiconductors include GaN, AlGaN, InGaN, and AlInGaN. Furthermore, these compound semiconductors may contain boron (B) atoms, thallium (Tl) atoms, arsenic (As) atoms, phosphorus (P) atoms, and antimony (Sb) atoms, as desired. The active layer desirably has a quantum well structure. Specifically, it may have a single quantum well structure (SQW structure) or a multiple quantum well structure (MQW structure). An active layer having a quantum well structure has a structure in which at least one well layer and one barrier layer are stacked, and the combination of (the compound semiconductor constituting the well layer, the compound semiconductor constituting the barrier layer) may be (In y Ga (1-y) N,GaN), (In y Ga (1-y) N,In z Ga (1-z) N) [where y>z], (In y Ga (1-y)Examples of such a compound semiconductor layer include GaN (GaN, AlGaN). The first compound semiconductor layer can be made of a compound semiconductor of a first conductivity type (e.g., n-type), and the second compound semiconductor layer can be made of a compound semiconductor of a second conductivity type (e.g., p-type) different from the first conductivity type. The first compound semiconductor layer and the second compound semiconductor layer are also called a first cladding layer and a second cladding layer. The first compound semiconductor layer and the second compound semiconductor layer may be layers of a single structure, layers of a multilayer structure, or layers of a superlattice structure. Furthermore, they may be layers having a composition gradient layer or a concentration gradient layer.

[0039] Alternatively, examples of group III atoms constituting the laminated structure include gallium (Ga), indium (In), and aluminum (Al), and examples of group V atoms constituting the laminated structure include arsenic (As), phosphorus (P), antimony (Sb), and nitrogen (N).Specific examples include AlAs, GaAs, AlGaAs, AlP, GaP, GaInP, AlInP, AlGaInP, AlAsP, GaAsP, AlGaAsP, AlInAsP, GaInAsP, AlInAs, GaInAs, AlGaInAs, AlAsSb, GaAsSb, AlGaAsSb, AlN, GaN, InN, AlGaN, GaNAs, and GaInNAs, and examples of compound semiconductors constituting the active layer include GaAs, AlGaAs, GaInAs, GaInAsP, GaInP, GaSb, GaAsSb, GaN, InN, GaInN, GaInNAs, and GaInNAsSb.

[0040] Examples of quantum well structures include a two-dimensional quantum well structure, a one-dimensional quantum well structure (quantum wire), and a zero-dimensional quantum well structure (quantum dot). Examples of materials that can be used to form quantum wells include, but are not limited to, Si; Se; chalcopyrite compounds such as CIGS (CuInGaSe), CIS (CuInSe2), CuInS2, CuAlS2, CuAlSe2, CuGaS2, CuGaSe2, AgAlS2, AgAlSe2, AgInS2, and AgInSe2; perovskite materials; III-V compounds such as GaAs, GaP, InP, AlGaAs, InGaP, AlGaInP, InGaAsP, GaN, InAs, InGaAs, GaInNAs, GaSb, and GaAsSb; CdSe, CdSeS, CdS, CdTe, In2Se3, In2S3, Bi2Se3, Bi2S3, ZnSe, ZnTe, ZnS, HgTe, HgS, PbSe, PbS, and TiO2.

[0041] The laminated structure is formed on the second surface of a substrate for manufacturing a light-emitting element, or alternatively, on the second surface of a compound semiconductor substrate. The second surface of the substrate for manufacturing a light-emitting element or the compound semiconductor substrate faces the first surface of the first compound semiconductor layer, and the first surface of the substrate for manufacturing a light-emitting element or the compound semiconductor substrate faces the second surface of the substrate for manufacturing a light-emitting element or the compound semiconductor substrate. Examples of substrates for manufacturing a light-emitting element include GaN substrates, sapphire substrates, GaAs substrates, SiC substrates, alumina substrates, ZnS substrates, ZnO substrates, AlN substrates, LiMgO substrates, LiGaO substrates, MgAlO substrates, InP substrates, and Si substrates, as well as substrates with an underlayer or buffer layer formed on the surface (main surface) of these substrates. However, GaN substrates are preferred due to their low defect density. Examples of compound semiconductor substrates include GaN substrates, InP substrates, and GaAs substrates. It is known that the properties of GaN substrates vary between polar, nonpolar, and semipolar depending on the growth surface. However, any of the main surfaces (second surfaces) of GaN substrates can be used to form compound semiconductor layers. Furthermore, depending on the crystal structure (e.g., cubic or hexagonal), the primary surface of the GaN substrate may have a crystal plane orientation known as the A-plane, B-plane, C-plane, R-plane, M-plane, N-plane, S-plane, or a plane off-axis in a specific direction. Examples of methods for forming the various compound semiconductor layers constituting the light-emitting device include, but are not limited to, metal-organic chemical vapor deposition (MOCVD, metal organic-chemical vapor deposition, MOVPE, metal organic-vapor phase epitaxy), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) in which halogen contributes to transport or reaction, atomic layer deposition (ALD), migration-enhanced epitaxy (MEE), and plasma-assisted physical vapor deposition (PPD).

[0042] GaAs and InP materials also have a zinc blende structure. The primary surfaces of compound semiconductor substrates made from these materials include (100), (111)AB, (211)AB, and (311)AB planes, as well as planes off-axis in specific directions. Note that "AB" refers to different 90° off-axis directions, and this off-axis direction determines whether the primary material of the plane is group III or group V. Controlling these crystal plane orientations and deposition conditions makes it possible to control compositional variations and dot shapes. As with GaN-based materials, deposition methods commonly used include MBE, MOCVD, MEE, and ALD, but are not limited to these methods.

[0043] Here, in forming a GaN-based compound semiconductor layer, examples of organic gallium source gases in the MOCVD method include trimethylgallium (TMG) gas and triethylgallium (TEG) gas, and examples of nitrogen source gases include ammonia gas and hydrazine gas. When forming a GaN-based compound semiconductor layer having n-type conductivity, silicon (Si) may be added as an n-type impurity (n-type dopant), and when forming a GaN-based compound semiconductor layer having p-type conductivity, magnesium (Mg) may be added as a p-type impurity (p-type dopant). When aluminum (Al) or indium (In) is contained as a constituent atom of the GaN-based compound semiconductor layer, trimethylaluminum (TMA) gas may be used as an Al source, and trimethylindium (TMI) gas may be used as an In source. Furthermore, monosilane gas (SiH4 gas) may be used as the Si source, and biscyclopentadienyl magnesium gas, methylcyclopentadienyl magnesium, or biscyclopentadienyl magnesium (Cp2Mg) may be used as the Mg source. Note that examples of n-type impurities (n-type dopants) other than Si include Ge, Se, Sn, C, Te, S, O, Pd, and Po, and examples of p-type impurities (p-type dopants) other than Mg include Zn, Cd, Be, Ca, Ba, C, Hg, and Sr.

[0044] When the stacked structure is composed of InP-based compound semiconductors or GaAs-based compound semiconductors, organometallic materials such as TMGa, TEGa, TMIn, and TMAl are commonly used as group III materials. Furthermore, arsine gas (AsH3 gas), phosphine gas (PH3 gas), and ammonia (NH3) are commonly used as group V materials. Furthermore, organometallic materials such as tertiarybutylarsine (TBAs), tertiarybutylphosphine (TBP), dimethylhydrazine (DMHy), and trimethylantimony (TMSb) are sometimes used as group V materials. These materials decompose at low temperatures, making them effective for low-temperature growth. For n-type dopants, monosilane (SiH4) is used as a Si source, and hydrogen selenide (H2Se) is used as a Se source. Furthermore, dimethylzinc (DMZn), biscyclopentadienylmagnesium (Cp2Mg), and the like are commonly used as p-type dopants. Materials similar to those used for GaN-based dopants are candidates.

[0045] The first surface of the first compound semiconductor layer may constitute the base surface. Alternatively, a compound semiconductor substrate (or a substrate for manufacturing a light-emitting device) may be disposed between the first surface of the first compound semiconductor layer and the first light-reflecting layer, and the base surface may be constituted by the surface of the compound semiconductor substrate (or a substrate for manufacturing a light-emitting device). In this case, for example, the compound semiconductor substrate may be a GaN substrate. Any of polar, semi-polar, and non-polar substrates may be used as the GaN substrate. The thickness of the compound semiconductor substrate may be 5×10 -5 m to 1×10 -4 Examples of the material for the base include, but are not limited to, a base material disposed between the first surface of the first compound semiconductor layer and the first light reflecting layer, or a compound semiconductor substrate and a base material disposed between the first surface of the first compound semiconductor layer and the first light reflecting layer, with the base surface being the surface of the base material. Examples of materials for the base material include transparent dielectric materials such as TiO2, Ta2O5, and SiO2, silicone-based resins, and epoxy-based resins.

[0046] In manufacturing the light-emitting element and the like of the present disclosure, the substrate for manufacturing a light-emitting element may be left in place, or the substrate for manufacturing a light-emitting element may be removed after an active layer, a second compound semiconductor layer, a second electrode, and a second light-reflecting layer are sequentially formed on the first compound semiconductor layer. Specifically, the active layer, the second compound semiconductor layer, the second electrode, and the second light-reflecting layer are sequentially formed on the first compound semiconductor layer formed on the substrate for manufacturing a light-emitting element, and then the second light-reflecting layer is fixed to a support substrate, after which the substrate for manufacturing a light-emitting element is removed to expose the first compound semiconductor layer (the first surface of the first compound semiconductor layer). The substrate for manufacturing light-emitting elements can be removed by wet etching using alkaline aqueous solutions such as sodium hydroxide solution or potassium hydroxide solution, ammonia solution + hydrogen peroxide solution, sulfuric acid solution + hydrogen peroxide solution, hydrochloric acid solution + hydrogen peroxide solution, phosphoric acid solution + hydrogen peroxide solution, etc.; dry etching methods such as chemical mechanical polishing (CMP), mechanical polishing, and reactive ion etching (RIE); lift-off methods using lasers, etc.; or a combination of these.

[0047] The support substrate for fixing the second light-reflecting layer may be composed of, for example, any of the various substrates exemplified as substrates for manufacturing light-emitting devices. Alternatively, it may be composed of an insulating substrate made of AlN or the like, a semiconductor substrate made of Si, SiC, Ge, or the like, a metal substrate, or an alloy substrate. However, a conductive substrate is preferred. Alternatively, a metal substrate or an alloy substrate is preferred from the viewpoints of mechanical properties, elastic deformation, plastic deformability, heat dissipation, and the like. The thickness of the support substrate can be, for example, 0.05 mm to 1 mm. Known methods for fixing the second light-reflecting layer to the support substrate can be used, such as solder bonding, room-temperature bonding, bonding using adhesive tape, wax bonding, and adhesive bonding. However, from the viewpoint of ensuring conductivity, solder bonding or room-temperature bonding is preferred. For example, when a conductive silicon semiconductor substrate is used as the support substrate, it is desirable to use a method that allows bonding at a low temperature of 400°C or less to suppress warping due to differences in thermal expansion coefficients. When a GaN substrate is used as the support substrate, the bonding temperature may be 400°C or higher.

[0048] When the substrate for manufacturing a light-emitting element remains, the first electrode may be formed on the first surface of the substrate opposite the second surface, or on the first surface of the compound semiconductor substrate opposite the second surface. When the substrate for manufacturing a light-emitting element remains, the first electrode may be formed on the first surface of the first compound semiconductor layer constituting the laminated structure. In this case, a first light-reflecting layer is formed on the first surface of the first compound semiconductor layer, and the first electrode may be formed, for example, to surround the first light-reflecting layer. The first electrode preferably has a single-layer or multilayer structure containing at least one metal (including alloys) selected from the group consisting of gold (Au), silver (Ag), palladium (Pd), platinum (Pt), nickel (Ni), titanium (Ti), vanadium (V), tungsten (W), chromium (Cr), aluminum (Al), copper (Cu), zinc (Zn), tin (Sn), and indium (In). Specific examples include Ti / Au, Ti / Al, Ti / Al / Au, Ti / Pt / Au, Ni / Au, Ni / Au / Pt, Ni / Pt, Pd / Pt, and Ag / Pd. Note that the layer before the " / " in the multilayer structure is located closer to the active layer. This also applies to the following description. The first electrode can be formed by a PVD method such as vacuum deposition or sputtering.

[0049] When the first electrode is formed to surround the first light reflecting layer, the first light reflecting layer and the first electrode may be in contact with each other. Alternatively, the first light reflecting layer and the first electrode may be spaced apart. In some cases, the first electrode may be formed up to the edge of the first light reflecting layer, or the first light reflecting layer may be formed up to the edge of the first electrode.

[0050] The second electrode may be made of a transparent conductive material, such as an indium-based transparent conductive material (specifically, for example, indium-tin oxide (ITO, indium tin oxide, Sn-doped In2O3, including crystalline ITO and amorphous ITO), indium-zinc oxide (IZO, indium zinc oxide), indium-gallium oxide (IGO), indium-doped gallium-zinc oxide (IGZO, In-GaZnO4), IFO (F-doped In2O3), ITiO (Ti-doped In2O3), InSn, or InSnZnO), or a tin-based transparent conductive material (specifically, for example, tin oxide (SnO X ), ATO (Sb-doped SnO2), FTO (F-doped SnO2)], zinc-based transparent conductive materials [specifically, for example, zinc oxide (including ZnO, Al-doped ZnO (AZO) and B-doped ZnO), gallium-doped zinc oxide (GZO), AlMgZnO (aluminum oxide and magnesium oxide-doped zinc oxide)], NiO, TiO X Examples of materials constituting the second electrode include transparent conductive films having a base layer of gallium oxide, titanium oxide, niobium oxide, antimony oxide, nickel oxide, etc., and transparent conductive materials such as spinel-type oxides and oxides having a YbFe2O4 structure. The second electrode can be formed by a PVD method such as vacuum deposition or sputtering. Alternatively, a low-resistance semiconductor layer can be used as the second electrode; in this case, specifically, an n-type GaN-based compound semiconductor layer can be used. Furthermore, when the layer adjacent to the n-type GaN-based compound semiconductor layer is p-type, the electrical resistance at the interface can be reduced by joining the two via a tunnel junction.

[0051] A first pad electrode and a second pad electrode may be provided on the first electrode and the second electrode to electrically connect them to an external electrode or circuit (hereinafter, sometimes referred to as an "external circuit, etc."). The pad electrodes preferably have a single-layer or multi-layer structure containing at least one metal selected from the group consisting of Ti (titanium), aluminum (Al), Pt (platinum), Au (gold), Ni (nickel), and Pd (palladium). Alternatively, the pad electrodes may have a multi-layer structure, such as a Ti / Pt / Au multi-layer structure, a Ti / Au multi-layer structure, a Ti / Pd / Au multi-layer structure, a Ti / Pd / Au multi-layer structure, a Ti / Ni / Au multi-layer structure, or a Ti / Ni / Au / Cr / Au multi-layer structure. When the first electrode is composed of an Ag layer or an Ag / Pd layer, it is preferable to form a cover metal layer, for example, made of Ni / TiW / Pd / TiW / Ni, on the surface of the first electrode, and then form a pad electrode, for example, made of a multilayer structure of Ti / Ni / Au or a multilayer structure of Ti / Ni / Au / Cr / Au, on the cover metal layer.

[0052] The light reflecting layers (Distributed Bragg Reflector layers, DBR layers) constituting the first light reflecting layer and the second light reflecting layer are made of, for example, a semiconductor multilayer film or a dielectric multilayer film. Examples of dielectric materials include oxides and nitrides of Si, Mg, Al, Hf, Nb, Zr, Sc, Ta, Ga, Zn, Y, B, Ti, etc. (e.g., SiN X , AlN X , AlGaN X , GaN X , B.N. X fluorides, etc., can be mentioned. Specifically, SiO X , TiO X , NbO X , ZrO X , TaO X , ZnO X , AlO X , HfO X , SiN X , AlN XAmong these dielectric materials, two or more types of dielectric films made of dielectric materials with different refractive indices can be alternately laminated to obtain a light-reflecting layer. For example, SiO X / SiN Y , SiO X / TaO X , SiO X / NbO Y , SiO X / ZrO Y , SiO X / AlN Y Multilayer films such as those described above are preferred. To obtain the desired light reflectance, the material, film thickness, number of layers, etc. constituting each dielectric film may be selected as appropriate. The thickness of each dielectric film can be adjusted as appropriate depending on the material used, etc., and is determined by the oscillation wavelength (emission wavelength) λ0 and the refractive index n of the material used at the oscillation wavelength λ0. Specifically, it is preferred to set the thickness to an odd multiple of λ0 / (4n). For example, in a light emitting device with an oscillation wavelength λ0 of 410 nm, the light reflective layer may be made of SiO X / NbO Y When the light-reflecting layer is made up of a plurality of layers, the thickness can be approximately 40 nm to 70 nm. The number of layers can be 2 or more, preferably approximately 5 to 20. The total thickness of the light-reflecting layer can be approximately 0.6 μm to 1.7 μm. The light reflectance of the light-reflecting layer is desirably 95% or more. The size and shape of the light-reflecting layer are not particularly limited, as long as they cover the current injection region or the element region (which will be described later).

[0053] The light-reflecting layer can be formed based on well-known methods, and specific examples include PVD methods such as vacuum deposition, sputtering, reactive sputtering, ECR plasma sputtering, magnetron sputtering, ion beam assisted deposition, ion plating, and laser ablation; various CVD methods; coating methods such as spraying, spin coating, and dipping; methods combining two or more of these methods; and methods combining these methods with one or more of full or partial pretreatment, irradiation with inert gas (Ar, He, Xe, etc.) or plasma, irradiation with oxygen gas, ozone gas, or plasma, oxidation treatment (heat treatment), and exposure treatment.

[0054] As described above, a current injection region is provided to regulate current injection into the active layer. The shape of the boundary between the current injection region and the current confinement region (non-current injection region) and the planar shapes of the openings provided in the element region and current confinement region are as described above. Here, the term "element region" refers to the region into which the confined current is injected, or the region in which light is confined due to a refractive index difference or the like, or the region sandwiched between the first light reflecting layer and the second light reflecting layer where laser oscillation occurs, or the region sandwiched between the first light reflecting layer and the second light reflecting layer that actually contributes to laser oscillation.

[0055] The side surfaces and exposed surfaces of the laminated structure may be covered with a covering layer (insulating film). The covering layer (insulating film) can be formed based on a well-known method. The refractive index of the material constituting the covering layer (insulating film) is preferably smaller than the refractive index of the material constituting the laminated structure. The material constituting the covering layer (insulating film) is preferably SiO2 containing SiO2. X based materials, SiN X based materials, SiO Y N Z based materials, TaO X , ZrO X , AlN X , AlO X , GaO XAlternatively, organic materials such as polyimide resins can also be used. The coating layer (insulating film) can be formed by, for example, PVD methods such as vacuum deposition and sputtering, or CVD methods, or can be formed based on a coating method. [Example]

[0056] Example 1 relates to a light-emitting device according to the first aspect of the present disclosure. The light-emitting device of the example is a surface-emitting laser device (vertical cavity laser, VCSEL) that emits laser light. A schematic partial end view of the light-emitting device of Example 1 is shown in FIG. 1, the arrangement of the current injection region, current confinement region, and second electrode that constitute the light-emitting device of Example 1 is shown in FIG. 2A, and schematic partial end views of the light-emitting device of Example 1 taken along arrows BB and CC in FIG. 2A are shown in FIGS. 2B and 2C. Although these views are essentially the same as FIGS. 2A, 2B, and 2C, various parameters are added to the views in FIGS. 3A, 3B, and 3C.

[0057] The various symbols used in the following description (see FIG. 3) are explained in Table 1. Reference numbers will be explained later.

[0058] [Light-emitting element] λ0: Oscillation wavelength L OR :cavity length θ Y : The angle of light emission on the YZ virtual plane θ X : The angle of light emission on the XZ virtual plane [Second electrode 32] L 32AB : The length of the second electrode 32 in the YZ virtual plane W 32AB : Length of the second electrode 32 in the XZ virtual plane r 32CD : Radius of the semicircular portion of the second electrode 32 on the XY virtual plane [Current injection region 51] L max-Y: Width of the current injection region 51 in the Y direction (length of the current injection region 51 in the YZ virtual plane) L min-X : Width of the current injection region 51 in the X direction (length of the current injection region 51 in the XZ virtual plane) L 51AB : The length of two parallel line segments 51A and 51B that make up the oval r 51CD : The radius of the semicircles 51C and 51D connecting one end and the other end of the two line segments 51A and 51B [First portion 91 of base surface 90] R1: the center 91 of the shape of the convex portion when the first portion 91 of the base surface 90 is cut by the XZ virtual plane c Radius of curvature R 91BC : Radius of curvature of the end of the first portion 91 of the base surface 90 when cut along the YZ virtual plane R2: The center 92 of the second portion 92 of the base surface 90 when cut along the XZ virtual plane c Radius of curvature [Light-emitting element unit] P X : Arrangement pitch of multiple light-emitting elements θ Y ': The angle of light emission on the YZ virtual plane θ X ' : The angle of light emission on the XZ virtual plane

[0059] The light emitting device 10A of Example 1 or the light emitting devices of Examples 2 to 12 described below has the following characteristics: a first compound semiconductor layer 21 having a first surface 21a and a second surface 21b opposite to the first surface 21a; an active layer (light-emitting layer) 23 facing the second surface 21b of the first compound semiconductor layer 21; and a second compound semiconductor layer 22 having a first surface 22a facing the active layer 23 and a second surface 22b opposite to the first surface 22a; a laminated structure 20 in which the above are laminated; a first light reflecting layer 41 formed on the first surface side of the first compound semiconductor layer 21; a second light reflecting layer 42 formed on the second surface side of the second compound semiconductor layer 22; a first electrode 31 electrically connected to the first compound semiconductor layer 21; and a second electrode 32 electrically connected to the second compound semiconductor layer 22; It is equipped with A current confinement region 52 is provided to control the flow of current into the active layer 23 .

[0060] In the light-emitting element 10A of Example 1, when the thickness-wise axis of the stacked structure 20 passing through the center of the current injection region 51 surrounded by the current constriction region 52 is defined as the Z-axis, the direction perpendicular to the Z-axis is defined as the X-direction, and the direction perpendicular to the X-direction and the Z-axis is defined as the Y-direction, the current injection region 51 has an elongated planar shape with its longitudinal direction extending in the Y-direction.

[0061] In the light emitting device 10A of Example 1, the width of the current injection region 51 along the Y direction is L max-Y , the width along the X direction is L min-X When L max-Y / L min-X ≧3 Preferably, L max-Y / L min-X ≧20 Satisfy.

[0062] In the light emitting device 10A of Example 1, the first light reflecting layer 41 has a convex shape extending in a direction away from the active layer 23, and the second light reflecting layer 42 has a flat shape. In this case, the cavity length L along the Z axis is OR Including, but not limited to, 1×10 -5 m(10μm)≦L OR ≦5×10 -5 m (50 μm) Examples include:

[0063] Furthermore, in the light emitting device 10A of Example 1, the planar shapes of the first light reflecting layer 41 and the second electrode 32 are similar (approximate) to the planar shape of the current injection region 51. The planar shape of the current injection region 51 is an ellipse. The length L of the two parallel line segments 51A and 51B that form the ellipse is 51AB , the radius r of the semicircles 51C and 51D connecting one end and the other end of the two line segments 51A and 51B. 51CD The length of the second electrode 32 in the YZ virtual plane (the length of the line segments 32A and 32B in the second electrode 32 when the second electrode 32 is cut by the YZ virtual plane) L 32AB , the length of the second electrode 32 in the XZ virtual plane (the length of the second electrode 32 when the second electrode 32 is cut by the XZ virtual plane) W 32AB , the radius r of the semicircular portion of the second electrode 32 in the XY virtual plane 32CD The orthogonal projection image of the current injection region 51 is included in the orthogonal projection image of the second electrode 32. Furthermore, the orthogonal projection image of the current confinement region 52 is included in the orthogonal projection image of the second electrode 32.

[0064] Here, the first surface 21a of the first compound semiconductor layer 21 constitutes the base surface 90. When the second surface 21b of the first compound semiconductor layer 21 is used as a reference, a first portion 91 of the base surface 90 on which the first light reflecting layer 41 is formed has an upwardly convex shape. That is, the base surface 90 has a convex shape extending in a direction away from the active layer 23. In Example 1, a second portion 92, which is a portion of the base surface 90 located outside the first portion 91, is flat and surrounds the first portion 91. The first light reflecting layer 41 is formed on the first portion 91 of the base surface 90, but is not formed on the second portion 92 of the base surface 90.

[0065] The shape (figure) of the first portion 91 of the base surface 90 when cut on the YZ imaginary plane is a line segment 91A and portions 91B and 91C of a circle extending from one end and the other end of the line segment 91A (see FIG. 3B). The line segment 92A and the line segment 91A are parallel to each other when the second portion 92 of the base surface 90 is cut on the YZ imaginary plane. Furthermore, the shape 91D of the convex portion when the first portion 91 of the base surface 90 is cut on the XZ imaginary plane is, for example, a portion of a circle (see FIG. 3C). The radius of curvature R of the ends 91B and 91C of the first portion 91 of the base surface 90 when cut on the YZ imaginary plane is 91BC More on this later.

[0066] 3C, the center 91 of the shape 91D (the curve drawn by the first portion 91) drawn by the convex portion when the first portion 91 of the base surface 90 is cut along the XZ virtual plane is c The radius of curvature R1 is 1.5×10 -5 m(15μm)≦R1≦1×10 -3 m(1mm) Preferably, 3×10 -5 m(30μm)≦R1≦1.5×10 -4 m (150 μm) It is desirable to satisfy the following.

[0067] The laminated structure 20 can be made of at least one material selected from the group consisting of GaN-based compound semiconductors, InP-based compound semiconductors, and GaAs-based compound semiconductors.

[0068] An example of the configuration of the light emitting element 10A of Example 1 will be described below.

[0069] The first compound semiconductor layer 21 has, for example, 2×10 Si. 16 cm -3 The active layer 23 is made of In. 0.04 Ga 0.96 N layer (barrier layer) and In 0.16 Ga 0.84The second compound semiconductor layer 22 has a five-layered multi-quantum well structure in which an N layer (well layer) is stacked. For example, the second compound semiconductor layer 22 has a magnesium content of 1×10 19 cm -3 The first compound semiconductor layer 21 is made of a p-GaN layer doped to a certain degree. The plane orientation of the first compound semiconductor layer 21 is not limited to the {0001} plane and can be, for example, the {20-21} plane, which is a semipolar plane. The first electrode 31 made of Ti / Pt / Au is electrically connected to an external circuit or the like via a first pad electrode (not shown) made of, for example, Ti / Pt / Au or V / Pt / Au. Meanwhile, the second electrode 32 is formed on the second compound semiconductor layer 22, and the second light-reflecting layer 42 is formed on the second electrode 32. The second light-reflecting layer 42 on the second electrode 32 has a flat shape. A second pad electrode (not shown) made of, for example, Ti / Pt / Au, Ni / Pt / Au, Pd / Ti / Pt / Au, Ti / Pd / Au, Ti / Ni / Au, or Ti / Au may be formed or connected on the edge of the second electrode 32 for electrical connection to an external circuit or the like. The first light reflecting layer 41 and the second light reflecting layer 42 are formed of a laminated structure of a Ta2O5 layer and a SiO2 layer, or a laminated structure of a SiN layer and a SiO2 layer. Although the first light reflecting layer 41 and the second light reflecting layer 42 have such a multilayer structure, they are represented as a single layer for simplicity of the drawings. The current injection region 51 is as described above. The planar shapes of the opening 31' provided in the first electrode 31, the first light reflecting layer 41, the opening 34A provided in the insulating layer (current confinement layer) 34, and the second light reflecting layer 42 are, but are not limited to, shapes that are similar (approximate shapes) to the planar shape of the current injection region 51. The first compound semiconductor layer 21 has a first conductivity type (specifically, n-type), and the second compound semiconductor layer 22 has a second conductivity type (specifically, p-type) different from the first conductivity type.

[0070] The stacked structure 20 is formed with a current injection region 51 and a current confinement region (non-current injection region) 52 surrounding the current injection region 51. Here, in the example shown in FIG. 1 , the current confinement region 52 is formed in the thickness direction from the second compound semiconductor layer 22 to a part of the first compound semiconductor layer 21. However, the current confinement region 52 may be formed in a region of the second compound semiconductor layer 22 on the second electrode side in the thickness direction, or may be formed in the entire second compound semiconductor layer 22, or may be formed in the second compound semiconductor layer 22 and the active layer 23. The current confinement region 52 can be formed based on an ion implantation method in which impurities [e.g., at least one type of ion (i.e., one type of ion or two or more types of ions) selected from the group consisting of boron, protons, phosphorus, arsenic, carbon, nitrogen, fluorine, oxygen, germanium, zinc, and silicon] are implanted, and the current confinement region 52 consisting of a region with reduced conductivity can be obtained.

[0071] Alternatively, as shown in FIG. 4, which is a schematic partial end view of a modified example 1 of the light-emitting device of Example 1, an insulating material (for example, SiO X and SiN X , AlO X ), an insulating layer (current confinement layer) 34 made of a material selected from the group consisting of SiO 2 and SiO 3 may be formed, and the insulating layer (current confinement layer) 34 is provided with an opening 34A for injecting a current into the second compound semiconductor layer 22. That is, the second compound semiconductor layer 22 is partitioned into a first region 22A and a second region 22B surrounding the first region 22A, a second electrode 32 is provided on the first region 22A of the second compound semiconductor layer 22, and the second region 22B of the second compound semiconductor layer 22 faces the second electrode 32 with the insulating layer 34 interposed therebetween.

[0072] Alternatively, to obtain the current confinement region, the second compound semiconductor layer 22 may be etched by RIE or the like to form a mesa structure, or at least a portion of the stacked second compound semiconductor layer 22 may be partially oxidized laterally to form the current confinement region. Alternatively, the current confinement region may be formed by irradiating the second surface of the second compound semiconductor layer with plasma (specifically, argon, oxygen, nitrogen, etc.), ashing the second surface of the second compound semiconductor layer, or reactive ion etching (RIE) the second surface of the second compound semiconductor layer. Irradiating the second surface of the second compound semiconductor layer with plasma deteriorates the conductivity of the second compound semiconductor layer, and the current confinement region becomes highly resistant.

[0073] Alternatively, these may be combined as appropriate. However, the second electrode 32 needs to be electrically connected to the portion of the second compound semiconductor layer 22 through which current flows due to current confinement (current injection region 51).

[0074] The second electrode 32 is connected to an external circuit or the like via a second pad electrode (not shown). The first electrode 31 is also connected to an external circuit or the like via a first pad electrode (not shown). Light may be emitted to the outside via the first light reflecting layer 41, or light may be emitted to the outside via the second light reflecting layer 42.

[0075] The specifications of the stacked structure and the like of the light-emitting element 10A of Example 1 are shown in Tables 2 and 3 below. In the light-emitting element of Example 1 whose specifications are shown in Table 2, the second pad electrode is provided in a position that does not interfere with the emission of light from the light-emitting element, and the structure allows light to be emitted either through the first light-reflecting layer 41 or through the second light-reflecting layer 42. On the other hand, in the light-emitting element of Example 1 whose specifications are shown in Table 3, the second pad electrode is formed so as to cover the second light-reflecting layer 42 and the second electrode 32, and the structure allows light to be emitted through the first light-reflecting layer 41. By providing such a second pad electrode, light generated in the active layer 23 is reflected toward the first light-reflecting layer 41, thereby improving the light-emitting efficiency.

[0076] Second pad electrode Ti / Pt / Au Second light-reflecting layer 42 SiO2 / Ta2O5 (11.5 pairs) Second electrode 32 ITO (thickness: 30 nm) Second compound semiconductor layer 22 p-GaN (thickness: 110 nm) Active layer 23: Multiple quantum well structure (total thickness: 15 nm) Well layer InGaN Barrier layer GaN First compound semiconductor layer 21 n-GaN (Si doped: 1×10 18 cm -3 ) First light-reflecting layer 41 SiO2 / SiN (14 pairs) First pad electrode V / Pt / Au λ0445nm L OR 25 μm θ Y 1 degree or less θ X 9 degrees L 32AB 46 μm W 32AB 30 μm r 32CD 15 μm L max-Y 50 μm L min-X 4 μm L 51AB 46 μm r 51CD 2 μm R135μm R 91BC 35 μm

[0077] Second pad electrode Ni / Pt / Au Second light-reflecting layer 42 SiO2 / Ta2O5 (14 pairs) Second electrode 32 ITO (thickness: 40 nm) Second compound semiconductor layer 22 p-GaN (thickness: 100 nm) Active layer 23: Multiple quantum well structure (total thickness: 20 nm) Well layer InGaN Barrier layer GaN First compound semiconductor layer 21 n-GaN (Ge doped: 5×10 18 cm -3 ) First light-reflecting layer 41 SiO2 / SiN (8 pairs) First pad electrode V / Pt / Au λ0455nm L OR 20 μm θ Y 1 degree or less θ X 7 degrees L 32AB 46 μm W 32AB 40 μm r 32CD 20 μm L max-Y 50 μm L min-X 4 μm L 51AB 46 μm r 51CD 2 μm R125μm R 91BC 60 μm

[0078] From Tables 2 and 3, the light emission angle θ on the YZ virtual plane Y It can be seen that the value can be reduced to 2 degrees or less.

[0079] A method for manufacturing the light emitting device 10A of Example 1 will be outlined below.

[0080] First, after forming the stacked structure 20, the second light reflecting layer 42 is formed on the second surface side of the second compound semiconductor layer 22.

[0081] [Process-100] Specifically, on the second surface 11b of the compound semiconductor substrate 11 having a thickness of about 0.4 mm, a first compound semiconductor layer 21 having a first surface 21a and a second surface 21b opposite to the first surface 21a; an active layer (light-emitting layer) 23 facing the second surface 21b of the first compound semiconductor layer 21; and a second compound semiconductor layer 22 having a first surface 22a facing the active layer 23 and a second surface 22b opposite to the first surface 22a; More specifically, the first compound semiconductor layer 21, the active layer 23, and the second compound semiconductor layer 22 are sequentially formed on the second surface 11b of the compound semiconductor substrate 11 by epitaxial growth using a well-known MOCVD method, thereby obtaining the layered structure 20 (see FIG. 21A).

[0082] [Process-110] Next, a current confinement region 52 is formed in the stacked structure 20 by a well-known ion implantation method using boron ions (see FIG. 21B).

[0083] [Process-120] Thereafter, the second electrode 32 is formed on the second compound semiconductor layer 22 by sputtering.

[0084] [Process-130] Next, the second light reflecting layer 42 is formed on the second electrode 32. Specifically, the second light reflecting layer 42 is formed from above the second electrode 32 to above the second pad electrode based on a combination of a film formation method such as sputtering or vacuum deposition and a patterning method such as wet etching or dry etching. The second light reflecting layer 42 on the second electrode 32 has a flat shape. In this way, the structure shown in FIG. 22 is obtained.

[0085] [Process-140] Next, the second light reflecting layer 42 is fixed to a support substrate 49 via a bonding layer 48 (see FIG. 23). Specifically, the second light reflecting layer 42 is fixed to a support substrate 49 made of a sapphire substrate using a bonding layer 48 made of an adhesive.

[0086] [Process-150] Next, the compound semiconductor substrate 11 is thinned by mechanical polishing or CMP, and then etched to remove the compound semiconductor substrate 11.

[0087] [Process-160] Thereafter, a sacrificial layer 81 is formed on a region of the base surface 90 (specifically, the first surface 21a of the first compound semiconductor layer 21) where the first light reflecting layer 41 is to be formed, where the first portion 91 is to be formed, and then the surface of the sacrificial layer 81 is made convex. Specifically, a resist material layer is formed on the first surface 21a of the first compound semiconductor layer 21 and patterned so as to remain on the region of the base surface 90 where the first portion 91 is to be formed (see FIG. 24A), and then the remaining resist material layer is subjected to a heat treatment, whereby a sacrificial layer 81′ having a convex surface is obtained (see FIG. 24B). Next, the sacrificial layer 81′ is etched back, and further etched back from the base surface 90 toward the inside (i.e., from the first surface 21a of the first compound semiconductor layer 21 toward the inside of the first compound semiconductor layer 21). This allows a convex portion to be formed in the first portion 91 of the base surface 90 when the second surface 21b of the first compound semiconductor layer 21 is used as a reference (see FIG. 24C ). A second portion 92 corresponding to a region between the first portions 91 of the base surface 90 is flat. The etch-back can be performed based on a dry etching method such as an RIE method, or based on a wet etching method using hydrochloric acid, nitric acid, hydrofluoric acid, phosphoric acid, a mixture thereof, or the like. Note that the active layer, the second compound semiconductor layer, the second light-reflecting layer, and the like are not shown in FIGS. 24A, 24B, and 24C, as well as FIGS. 25A, 25B, 25C, 26A, 26B, 26C, 27A, and 27B, which will be described later.

[0088] [Process-170] Next, the first light reflecting layer 41 is formed on the convex portions 91 of the base surface 90. Specifically, the first light reflecting layer 41 is formed on the entire surface of the base surface 90 by a film formation method such as sputtering or vacuum deposition, and then the first light reflecting layer 41 is patterned to obtain the first light reflecting layer 41 on the convex portions 91 of the base surface 90. Thereafter, the first electrode 31 is formed on the area of ​​the base surface 90 where the first light reflecting layer 41 is not formed. In this manner, the light emitting device 10A of Example 1 shown in FIG. 1 is obtained. By making the first electrode 31 protrude beyond the first light reflecting layer 41, the first light reflecting layer 41 can be protected. Then, the first electrode 31 may be electrically connected to an external electrode or circuit (a circuit that drives the light emitting device). Specifically, the first compound semiconductor layer 21 may be connected to an external circuit or the like via the first electrode 31 and a first pad electrode (not shown), and the second compound semiconductor layer 22 may be connected to an external circuit or the like via the second electrode 32 and a second pad electrode. Next, the light emitting device 10A of Example 1 is completed by packaging and sealing.

[0089] Incidentally, there are three notable discoveries that provide the physical background to semiconductor lasers.

[0090] The first is stimulated emission, predicted by Einstein. This is a phenomenon in which a specific mode is enhanced when a transition occurs from one state to another. This phenomenon occurs when the source state of the transition is population inverted and the destination state is a boson. In the case of semiconductor lasers, laser light with a specific mode is generated by causing the electron-hole transition (stimulated emission) of a population inverted state to light. In this case, in order to induce the electron-hole transition to a population inverted state, it is necessary to locally inject a current, i.e., to confine the electrons and light in a narrow region.

[0091] The second is a consideration of the uncertainty of states predicted by Schrödinger. Quantum particles, including light, can be in multiple states simultaneously, and it was predicted that their states can be determined by observation. This is a famous thought experiment known as "Schrödinger's cat." When a quantum particle can be in multiple states simultaneously, these states are often described as "overlapping," "coupled," or "coherent in phase."

[0092] The third is the uncertainty principle proposed by Heisenberg. This states that there is a causal relationship between the degree of uncertainty of each physical quantity possessed by a quantum. In particular, it predicted that there is an inversely proportional relationship between the uncertainty of position and momentum. In the case of semiconductor lasers, this is nothing other than the relationship between the minimum width of a light beam (or the uncertainty of the position of a light beam in a plane perpendicular to the direction of propagation) and the emission angle (radiation angle). Increasing the minimum width of a light beam suppresses the emission angle, resulting in light that propagates in a straight line, a phenomenon known as diffraction that predates quantum mechanics.

[0093] According to the Heisenberg uncertainty principle, increasing the minimum width of the optical beam (or the uncertainty of its position in a plane perpendicular to the propagation direction), i.e., widening the beam width, is effective in narrowing the output angle. To achieve this goal, it is important to expand the optical confinement region. For example, in the case of a ridge-waveguide-type edge laser, which is widely used today, this can be done by expanding the ridge width. In the case of an oxide-confined surface-emitting laser, this can be done by expanding the non-oxidized confinement region, i.e., the current injection region. However, when the current injection region is expanded, the laser light may not be distributed widely within the surface-emitting laser, and multiple modes may be generated independently in various regions with localized non-coaxial spatial arrangements. In this case, the spatial uncertainty is reduced, resulting in an increase in the output angle, rather than a corresponding increase in the optical confinement region. For example, in the case of a surface-emitting laser element, due to phenomena such as undulations in the light-reflecting layer, defects in the compound semiconductor crystal, and non-uniform conductivity, different modes may become dominant in one region and another region of the surface-emitting laser element. In such cases, the quantum state of the laser light does not expand as much as the size of the light confinement region, so the emission angle of the light beam becomes larger than if the light spread throughout the entire light confinement region. In other words, simply expanding the optical confinement region is not sufficient to achieve wide light confinement.

[0094] Furthermore, in semiconductor laser devices, the light confinement region and the current confinement region overlap each other. Therefore, in many cases, it is necessary to expand the current injection region. However, injecting current into a large region requires a larger current to achieve population inversion, which leads to problems such as increased power consumption, increased heat generation, and reduced reliability.

[0095] In the light-emitting device of Example 1, in order to realize a wide light confinement region, it is necessary to not only expand the optical confinement region but also the current injection region. For this purpose, the current injection region has a unique shape, that is, an elongated planar shape with its longitudinal direction extending in the Y direction. As a result, the width of the light beam emitted from the light-emitting device in the Y direction is expanded, and the emission angle of the light beam in the Y direction can be reduced. That is, the emission angle θ of the light in the YZ virtual plane Y The light emission angle θ on the XZ virtual plane X This makes it possible to obtain a light emitting device that emits a light beam with high linearity in the YZ virtual plane, something that is not possible with conventional light emitting devices.

[0096] Furthermore, if the shape of the end region of the optical field narrowing region in the Y direction is circular in plan view (spherical in three dimensions), it becomes possible to confine light that attempts to escape from the end region to the outside of the light-emitting element within the light-emitting element, thereby reducing light loss and improving the light-emitting efficiency of the light-emitting element.

[0097] Furthermore, the cross-sectional shape of the emitted light from the light-emitting device of Example 1 (the shape of the emitted light when the emitted light is assumed to be cut by a virtual plane perpendicular to the direction of propagation of the emitted light) is a "rod" or "I" shape extending in the Y direction. For example, if a wider range in the X direction is desired to be irradiated, it is possible to easily irradiate a long distance without an external optical system such as a lens, or by using a simple external optical system, while satisfying such requirements. It is also possible to obtain a light beam with high linearity and low radiation in the Y direction, and a light beam with a high-quality Gaussian profile in the X direction. Furthermore, compared to conventional light-emitting devices, a larger volume of the active layer (light-emitting layer) can be made to contribute to light emission, thereby achieving an increase in the output power of the light-emitting device (e.g., 100 milliwatts or more). Furthermore, since the distance from the second electrode to each region of the current injection region can be shortened, current can be uniformly passed through a large area of ​​the active layer, resulting in more efficient operation of the light-emitting device compared to conventional light-emitting devices.

[0098] In Modification 2 of the light-emitting device of Example 1, a schematic partial end view of which is shown in Figure 5, the compound semiconductor substrate 11 is disposed (remained) between the first surface 21a of the first compound semiconductor layer 21 and the first light reflecting layer 41, and the base surface 90 is composed of the surface (first surface 11a) of the compound semiconductor substrate 11. Note that Figure 5 illustrates a light-emitting device based on the light-emitting device of Modification 1 of Example 1, but the present invention is not limited to this.

[0099] In Modification 2 of the light-emitting device of Example 1, the compound semiconductor substrate 11 is thinned and mirror-finished in a step similar to [Step 150] of Example 1. The surface roughness Ra of the first surface 11a of the compound semiconductor substrate 11 is preferably 10 nm or less. The surface roughness Ra is specified in JIS B-610:2001 and can be measured, for example, by observation using an AFM or a cross-sectional TEM. A sacrificial layer is then formed on the exposed surface (first surface 11a) of the compound semiconductor substrate 11 in [Step 160] of Example 1. Subsequently, steps similar to those from [Step 160] onward in Example 1 are performed to provide a base surface 90 consisting of a first portion 91 and a second portion 92 on the compound semiconductor substrate 11 instead of the first compound semiconductor layer 21 in Example 1, thereby completing the light-emitting device. The first electrode 31 may be formed on the compound semiconductor substrate 11.

[0100] Alternatively, the first light reflecting layer 41 may be formed on a sapphire substrate serving as a substrate for manufacturing a light emitting device. In this case, the first electrode 31 may be connected to the first compound semiconductor layer 21 in a region not shown.

[0101] Alternatively, in a modified example 3 of the light-emitting element of Example 1, a schematic partial end view is shown in FIG. 6 . A substrate 95 is disposed between the first surface 21 a of the first compound semiconductor layer 21 and the first light-reflecting layer 41, and the base surface 90 is formed by the surface of the substrate 95. Alternatively, in a modified example 4 of the light-emitting element of Example 1, a schematic partial end view is shown in FIG. 7 . A compound semiconductor substrate 11 and a substrate 95 are disposed between the first surface 21 a of the first compound semiconductor layer 21 and the first light-reflecting layer 41, and the base surface 90 is formed by the surface of the substrate 95. Examples of materials that can be used for the substrate 95 include transparent dielectric materials such as TiO 2 , Ta 2 O 5 , and SiO 2 , silicone-based resins, and epoxy-based resins. Although FIGS. 6 and 7 also illustrate a light-emitting element based on the modified example 1 of Example 1, the present invention is not limited thereto.

[0102] In the light-emitting device of Modification 3 of Example 1 shown in FIG. 6, the compound semiconductor substrate 11 is removed in a step similar to [Step 150] of Example 1, and a base material 95 having a base surface 90 is formed on the first surface 21a of the first compound semiconductor layer 21. Specifically, for example, a TiO2 layer or Ta2O5 layer is formed on the first surface 21a of the first compound semiconductor layer 21. Next, a patterned resist layer is formed on the TiO2 or Ta2O5 layer where the first portion 91 will be formed, and the resist layer is heated to reflow the resist layer, thereby obtaining a resist pattern. The resist pattern is given a shape identical to (or similar to) the shape of the first portion. Then, the resist pattern and the TiO2 or Ta2O5 layer are etched back to obtain a base material 95 (made of a TiO2 or Ta2O5 layer) on which the first portion 91 and the second portion 92 are provided on the first surface 21a of the first compound semiconductor layer 21. Next, the first light-reflecting layer 41 may be formed on the desired area of ​​the substrate 95 by a known method.

[0103] Alternatively, in a fourth modification of the light-emitting device of the first embodiment shown in FIG. 7, the compound semiconductor substrate 11 is thinned and mirror-finished in a step similar to [Step 150] of the first embodiment, and then a base material 95 having a base surface 90 is formed on the exposed surface (first surface 11a) of the compound semiconductor substrate 11. Specifically, a TiO2 layer or Ta2O5 layer, for example, is formed on the exposed surface (first surface 11a) of the compound semiconductor substrate 11. Next, a patterned resist layer is formed on the TiO2 or Ta2O5 layer where the first portion 91 will be formed, and the resist layer is heated to reflow the resist layer, thereby obtaining a resist pattern. The resist pattern is given a shape identical to (or similar to) the shape of the first portion. Then, the resist pattern and the TiO2 or Ta2O5 layer are etched back to obtain a base material 95 (made of a TiO2 or Ta2O5 layer) on which the first portion 91 and the second portion 92 are provided on the exposed surface (first surface 11a) of the compound semiconductor substrate 11. Next, the first light-reflecting layer 41 may be formed on the desired area of ​​the substrate 95 by a known method. [Example]

[0104] Example 2 is a modification of Example 1. The arrangement of the current injection region, current confinement region, and second electrode that constitute the light-emitting device of Example 2 is shown typically in FIG. 8 or FIG. 9. In the light-emitting device of Example 2, the planar shape of the current injection region 51 is rectangular. On the other hand, the planar shape of the second electrode 32 is oval (FIG. 8) or rectangular with rounded corners (see FIG. 9). The current confinement region 52 surrounds the current injection region 51. As in Example 1, the orthogonal projection image of the current injection region 51 is included in the orthogonal projection image of the second electrode 32. Furthermore, the orthogonal projection image of the second electrode 32 is included in the orthogonal projection image of the current confinement region 52.

[0105] The specifications of the stacked structure and the like of the light-emitting element of Example 2 are shown in Table 4 below. In the light-emitting element having the specifications shown in Table 4, the second pad electrode is formed so as to cover the second light-reflecting layer 42 and the second electrode 32, and light is emitted via the first light-reflecting layer 41. The sides of the current injection region 51 parallel to the Y direction can be configured as line segments or curved lines. The schematic partial end views taken along arrow BB in FIGS. 8 and 9 and the schematic partial end views taken along arrow CC in FIGS. 8 and 9 are substantially the same as the schematic partial end views shown in FIGS. 2B and 2C.

[0106] Second pad electrode Ti / Au Second light-reflecting layer 42 SiO2 / Ta2O5 (14 pairs) Second electrode 32 ITO (thickness: 20 nm) Second compound semiconductor layer 22 p-GaN (thickness: 100 nm) Active layer 23: Multiple quantum well structure (total thickness: 25 nm) Well layer InGaN (Si doped: 2×10 18 cm -3 ) Barrier layer GaN First compound semiconductor layer 21 n-GaN First light-reflecting layer 41 SiO2 / SiN (9 pairs) First pad electrode V / Pt / Au λ0405nm L OR 35 μm θ Y 1 degree or less θ X 15 degrees L 32AB 500 μm W 32AB 25 μm r 32CD 25 μm L max-Y 25 μm L min-X 6 μm L 51AB 25 μm r 51CD -- R145μm R120μm R 91BC 20 μm

[0107] The light emitting device of Example 2 has a lower L than the light emitting device of Example 1 shown in Table 2. max-Y The value of is small, and L min-X The value of θ is large. Y The value of θ X The value of L is also larger than that of the light-emitting device of Example 1 shown in Table 2. max-Y The value of L min-X It was found that by appropriately designing the value of , the output angle of the light beam from the light-emitting device can be set to a desired value, i.e., the output angle can be controlled. Furthermore, by making the shape of the end region of the optical field confinement region in the Y direction circular in plan (spherical in three dimensions), it is possible to confine light that attempts to escape from the end region to the outside of the light-emitting device within the light-emitting device, reducing light loss and improving the light-emitting efficiency of the light-emitting device. Moreover, because the planar shape of the current injection region is rectangular, it is possible to prevent excessive current from flowing into the end region of the current injection region in the Y direction, suppressing localization of the light-emitting state in the end region, and thereby maintaining coherence in the light-emitting state throughout the device region. Furthermore, it is possible to improve the manufacturing yield of light-emitting devices.

[0108] Two light-emitting elements of Example 2 were arranged along the Y direction so that their YZ virtual planes overlapped. The distance between the second electrodes 32 of the two light-emitting elements along the Y direction was set to 5 μm. As a result, the uncertainty of the light position in the Y direction could be increased compared to the case of one light-emitting element, and θ Y The value of θ was 0.01 degrees or less. In addition, even if the total length of the current injection region 51 in the Y direction is the same as 50 μm, by arranging two light emitting elements (see Example 2) rather than one light emitting element (see Example 1), the value of θ Y The value of became smaller.

[0109] FIG. 10A shows a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode constituting Modification 1 of the light-emitting element of Example 2, and FIGS. 10B and 10C show schematic partial end views of Modification 1 of the light-emitting element of Example 2 taken along arrows BB and CC in FIG. 10A. In Modification 1, the current injection region 51 and the second electrode 32 have rectangular planar shapes. The orthogonal projection images of the sides of the second electrode 32 parallel to the X direction coincide with the orthogonal projection images of the sides of the current injection region 51 parallel to the X direction (see FIGS. 10A and 10B). Alternatively, the distance between the orthogonal projection images of the sides of the current injection region 51 parallel to the X direction and the orthogonal projection images of the sides of the second electrode 32 parallel to the X direction is within 5 μm. That is, based on the orthogonal projection image of the edge of the current injection region 51 parallel to the X direction, the orthogonal projection image of the edge of the second electrode 32 parallel to the X direction may be located within 5 μm outward in the Y direction, or may be located within 5 μm inward. This configuration prevents excessive current from flowing into the edge regions of the rectangular current injection region 51 in the Y direction, suppressing localization of the light-emitting state in the edge regions, thereby maintaining coherence in the light-emitting state throughout the device region. This also improves the manufacturing yield of the light-emitting device. Table 5 below shows the specifications of the stacked structure and other components of Modification 1 of the light-emitting device in Example 2. The side surface of the current injection region 51, including the edge parallel to the X direction, may be in contact with the current constriction region 52, and the end surface of the current injection region 51, including the edge parallel to the X direction, may be formed from a cut surface of the stacked structure 20. That is, the end surface of the current injection region 51, including the edge parallel to the X direction, may be in contact with the atmosphere, for example. Furthermore, the sides of the current injection region 51 parallel to the Y direction can be configured to be made up of line segments or curved lines.

[0110] Second pad electrode Ti / Pt / Au Second light-reflecting layer 42 SiO2 / Ta2O5 (11.5 pairs) Second electrode 32 ITO (thickness: 30 nm) Second compound semiconductor layer 22 p-GaN (thickness: 140 nm) Active layer 23: Multiple quantum well structure (total thickness: 15 nm) Well layer InGaN (Si doped: 1×10 18 cm -3 ) Barrier layer GaN First compound semiconductor layer 21 n-GaN First light-reflecting layer 41 SiO2 / SiN (14 pairs) First pad electrode V / Pt / Au λ0515nm L OR 15 μm θ Y 2 degrees or less θ X 15 degrees L 32AB 50 μm W 32AB 25 μm r 32CD -- L max-Y 50 μm L min-X 4 μm L 51AB 50 μm r 51CD -- R125μm

[0111] FIG. 11A shows a schematic diagram of the arrangement of the current injection region, current confinement region, and second electrode constituting Modification 2 of the light-emitting element of Example 2, and FIG. 11B shows a schematic partial end view along arrow BB. Modification 2 is a modification of Modification 1, in which an end face including a side parallel to the X direction of the current injection region 51 is in contact with a layer (laminated film) 60 in which first dielectric layers and second dielectric layers are alternately arranged in the Y direction. The outer surface of this laminated film 60 may be in contact with the current confinement region 52 or may be in contact with the atmosphere, for example. In a configuration in which the outer surface of the laminated film 60 is in contact with the current confinement region 52, the laminated film 60 has a similar configuration and structure to the light-reflecting layer, although the lamination direction (alternating arrangement direction) is different, for example. Specifically, a recess (groove) is formed in a portion of the laminated structure, and the recess (groove) is sequentially filled with the same material as the light-reflecting layer, for example, by sputtering. When the laminated film is cut along a virtual plane perpendicular to the stacking direction of the laminated structure, a laminated film in which the dielectric layers are arranged alternately can be obtained. Furthermore, in a configuration in which the outer surface of the laminated film 60 is in contact with the atmosphere, the end face including the side parallel to the X direction of the current injection region 51 is exposed by etching the laminated structure or by cutting the laminated structure. Then, layers made of the same material as the light-reflecting layer are sequentially formed on the end face by, for example, sputtering, to obtain the laminated film 60. Furthermore, the side parallel to the Y direction of the current injection region 51 can be configured as a line segment or a curve.

[0112] By adopting such a structure, it is possible to suppress the scattering of light in the Y direction, and to improve the light emitting efficiency of the light emitting device. In addition, since the edge region of the current injection region can be utilized as the element region, it is possible to obtain a light emitting device with a smaller chip area compared to other embodiments when the area of ​​the element region is the same. For example, L max-Y When the curvature radius R1 of the optical field constriction structure (first light reflecting layer having a concave mirror) is 25 μm, if Modification 2 is applied, L max-Y As a result, the substrate area required for manufacturing the light-emitting element is halved, which makes it possible to reduce manufacturing costs. [Example]

[0113] In the light-emitting element described in Examples 1 and 2, if a strong external force is applied to the rising portion of the first portion 91 of the flat base surface 90 for some reason, stress may be concentrated in the rising portion of the first portion 91, potentially causing damage to the first compound semiconductor layer, etc.

[0114] Example 3 is a modification of Examples 1 and 2. A schematic partial end view of a light-emitting device 10B of Example 3 is shown in FIG. 12. In Examples 1 and 2, the second portion 92 of the base surface 90 is flat. However, in Example 3, when the second surface 21b of the first compound semiconductor layer 21 is used as a reference, the second portion 92 of the base surface 90 is recessed toward the second surface 21b of the first compound semiconductor layer 21. Differentiable from the first portion 91 to the second portion 92, the portion of the base surface 90 where an inflection point exists from the first portion 91 to the second portion 92 is the boundary between the first portion 91 and the second portion 92. The shape of the portion [from the periphery to the center of the first portion / second portion] specifically corresponds to the case (A) described above.

[0115] The first light reflecting layer 41 is formed on a first portion 91 of the base surface 90, but an extension of the first light reflecting layer 41 may be formed on a second portion 92 of the base surface 90 that occupies the peripheral region 99, or the first light reflecting layer 41 may not be formed on the second portion 92. In Example 3, the first light reflecting layer 41 is not formed on the second portion 92 of the base surface 90 that occupies the peripheral region 99.

[0116] In the light emitting device 10B of Example 3, the boundary 90 between the first portion 91 and the second portion 92 bd teeth, (1) When the first light reflecting layer 41 does not extend to the peripheral region 99, the outer periphery of the first light reflecting layer 41 (2) When the first light-reflecting layer 41 extends to the peripheral region 99, the portion of the base surface 90 where an inflection point exists from the first portion 91 to the second portion 92 Here, the light emitting element 10B of Example 3 specifically corresponds to the case (1).

[0117] In the light-emitting device 10B of Example 3, the first surface 21a of the first compound semiconductor layer 21 constitutes the base surface 90. The shape of the first portion 91 of the base surface 90 when the base surface 90 is cut along a virtual plane (e.g., an XZ virtual plane in the illustrated example) including the stacking direction of the stacked structure 20 is differentiable. More specifically, the shape may be a part of a circle, a part of a parabola, a part of a sine curve, a part of an ellipse, or a part of a catenary curve, or a combination of these curves. A part of these curves may be replaced with a line segment. The shape (figure) of the second portion 92 is also differentiable. More specifically, the shape may be a part of a circle, a part of a parabola, a part of a sine curve, a part of an ellipse, or a part of a catenary curve, or a combination of these curves. A part of these curves may be replaced with a line segment. Furthermore, the boundary between the first portion 91 and the second portion 92 of the base surface 90 is also differentiable.

[0118] In the light-emitting device of Example 3, the base surface is uneven and differentiable. Therefore, if a strong external force is applied to the light-emitting device for some reason, the problem of stress concentration at the rising portions of the convex portions can be reliably avoided, and there is no risk of damage to the first compound semiconductor layer, etc. In particular, the light-emitting device unit described below is connected and bonded to an external circuit, etc. using bumps, and during bonding, a large load (e.g., approximately 50 MPa) must be applied to the light-emitting device unit. In the light-emitting device of Example 3, even if such a large load is applied, there is no risk of damage to the light-emitting device. Furthermore, because the base surface is uneven, the generation of stray light is further suppressed, and optical crosstalk between light-emitting devices can be more reliably prevented.

[0119] A method for manufacturing the light emitting device of Example 3 will be described below.

[0120] First, steps similar to [Step 100] to [Step 150] of Example 1 are performed. Then, a first sacrificial layer 81 is formed on a first portion 91 of a base surface 90 (specifically, the first surface 21a of the first compound semiconductor layer 21) on which the first light reflecting layer 41 is to be formed, and the surface of the first sacrificial layer is then made convex. Specifically, a first resist material layer is formed on the first surface 21a of the first compound semiconductor layer 21 and patterned to leave the first resist material layer on the first portion 91, thereby obtaining the first sacrificial layer 81 shown in FIG. 24A. The first sacrificial layer 81 is then subjected to a heat treatment, thereby obtaining the structure shown in FIG. 24B. Next, an ashing treatment (plasma irradiation treatment) is performed on the surface of the first sacrificial layer 81′ to alter the surface of the first sacrificial layer 81′. This prevents damage, deformation, or the like from occurring in the first sacrificial layer 81′ when a second sacrificial layer 82 is formed in the next step.

[0121] Next, a second sacrificial layer 82 is formed on the second portion 92 of the base surface 90 exposed between the first sacrificial layers 81′ and on the first sacrificial layer 81′, to make the surface of the second sacrificial layer 82 uneven (see FIG. 25A). Specifically, the second sacrificial layer 82 is formed of a second resist material layer having an appropriate thickness on the entire surface. In the example of the arrangement shown in FIG. 12, the average film thickness of the second sacrificial layer 82 is 2 μm, and the average film thickness of the second sacrificial layer 82 is 5 μm.

[0122] Alternatively, after forming a first sacrificial layer 81 on the first surface 21a of the first compound semiconductor layer 21, the surface of the first sacrificial layer 81 is made convex (see FIGS. 24A and 24B). Thereafter, the first sacrificial layer 81' is etched back, and the first compound semiconductor layer 21 is further etched back inward from the first surface 21a, thereby forming a convex portion 91' when the second surface 21b of the first compound semiconductor layer 21 is used as a reference. In this way, the structure shown in FIG. 26A can be obtained. Then, a second sacrificial layer 82 is formed on the entire surface (see FIG. 26B).

[0123] The material constituting the first sacrificial layer 81 and the second sacrificial layer 82 is not limited to a resist material, and may be an oxide material (e.g., SiO2, SiN, TiO2, etc.), a semiconductor material (e.g., Si, GaN, InP, GaAs, etc.), a metal material (e.g., Ni, Au, Pt, Sn, Ga, In, Al, etc.), or any other material appropriate for the first compound semiconductor layer 21. Furthermore, by using a resist material having an appropriate viscosity as the resist material constituting the first sacrificial layer 81 and the second sacrificial layer 82, and by appropriately setting and selecting the thickness of the first sacrificial layer 81, the thickness of the second sacrificial layer 82, the diameter of the first sacrificial layer 81′, etc., the value of the radius of curvature of the base surface 90 and the shape of the irregularities of the base surface 90 (e.g., diameter and height) can be set to desired values ​​and shapes.

[0124] Thereafter, the second sacrificial layer 82 and the first sacrificial layer 81′ are etched back, and further etched back from the base surface 90 toward the inside (i.e., from the first surface 21a of the first compound semiconductor layer 21 toward the inside of the first compound semiconductor layer 21). This forms a convex portion 91a in the first portion 91 of the base surface 90 and at least a concave portion (in Example 3, a concave portion 92a) in the second portion 92 of the base surface 90, relative to the second surface 21b of the first compound semiconductor layer 21. In this way, the structure shown in FIG. 25B or 26C can be obtained. If the radius of curvature R1 of the first portion 91 of the base surface 90 needs to be further increased, this process can be repeated. The etch-back can be performed by dry etching, such as RIE, or by wet etching using hydrochloric acid, nitric acid, hydrofluoric acid, phosphoric acid, or a mixture thereof.

[0125] Next, a first light reflecting layer 41 is formed on the first portion 91 of the base surface 90. Specifically, the first light reflecting layer 41 is formed on the entire surface of the base surface 90 by a film formation method such as sputtering or vacuum deposition (see FIG. 25C), and then the first light reflecting layer 41 is patterned to obtain the first light reflecting layer 41 on the first portion 91 of the base surface 90 (see FIG. 27A). Thereafter, a first electrode 31 common to each light-emitting element is formed on the second portion 92 of the base surface 90 (see FIG. 27B). In this manner, the light-emitting element unit or light-emitting element 10B of Example 3 can be obtained. If the first electrode 31 is made to protrude beyond the first light reflecting layer 41, the first light reflecting layer 41 can be protected. Then, the first electrode 31 may be electrically connected to an external electrode or circuit (a circuit that drives the light-emitting element). Specifically, the first compound semiconductor layer 21 may be connected to an external circuit or the like via the first electrode 31 and a first pad electrode (not shown), and the second compound semiconductor layer 22 may be connected to an external circuit or the like via the second electrode 32 and a second pad electrode. Next, the light-emitting device of Example 3 is completed by packaging and sealing. [Example]

[0126] Example 4 relates to a light-emitting element unit of the present disclosure. The arrangement of the current injection region, the current confinement region, and the second electrode in the light-emitting element constituting the light-emitting element unit of Example 4 is shown schematically in Figures 13A and 13B. Also, Figure 14 shows a partial end view of the light-emitting element unit along the X direction.

[0127] The light-emitting element unit of Example 4 is a light-emitting element unit consisting of a plurality of light-emitting elements, each of which is composed of the light-emitting element of Examples 1 to 3 including various modified examples. The plurality of light-emitting elements are arranged at intervals in the X direction. In the illustrated example, one light-emitting element unit is composed of four light-emitting elements, but the number of light-emitting elements constituting the light-emitting element unit is not limited to this.

[0128] In the light-emitting element unit of Example 4, the width of the current injection region 51 in each light-emitting element along the Y direction is L max-Y , the width along the X direction is Lmin-X When L max-Y / L min-X ≧3 Preferably, L max-Y / L min-X ≧20 Satisfied, The arrangement pitch of the multiple light emitting elements along the X direction is P X When P X / L min-X ≧1.5 Preferably, P X / L min-X ≧5 Satisfy.

[0129] In addition, in the light-emitting element unit of Example 4, in the entire light-emitting element unit, The light emission angle θ on the YZ virtual plane Y ' is less than 2 degrees, The light emission angle θ on the XZ virtual plane X ' is less than 0.1 degrees.

[0130] 13A, the first electrode 31 is common to a plurality of light-emitting elements, and the second electrode 32 is provided individually for each light-emitting element. Each second electrode 32 is connected to an external circuit or the like via a second pad electrode (not shown). The second pad electrode is provided at a position that does not interfere with the emission of light from the light-emitting elements, and is configured to allow light to be emitted either through the first light-reflecting layer 41 or through the second light-reflecting layer 42. In some cases, the second pad electrode is formed to cover four light-emitting elements (specifically, the second light-reflecting layer 42 and the second electrode 32), and a structure in which light is emitted through the first light-reflecting layer 41 can also be used.

[0131] 13B , the first electrode 31 is common to a plurality of (four in the illustrated example) light-emitting elements, and the second electrode 32 is common to a plurality of (four in the illustrated example) light-emitting elements. That is, the second electrode 32 common to the four light-emitting elements is formed so as to cover the second surfaces 22b of the second compound semiconductor layers 22 in the four light-emitting elements, and the second electrode 32 is connected to an external circuit or the like via a second pad electrode (not shown). The second pad electrode is provided at a position that does not interfere with the emission of light from the light-emitting elements, and is configured to allow light to be emitted either through the first light-reflecting layer 41 or through the second light-reflecting layer 42. In some cases, the second pad electrode is formed so as to cover the four light-emitting elements (specifically, the second light-reflecting layer 42 and the second electrode 32), and a structure in which light is emitted through the first light-reflecting layer 41 can be used. Alternatively, in some cases, instead of the second pad electrode, a transparent conductive material layer made of, for example, ITO may be formed so as to cover the four light-emitting elements (specifically, the second light-reflecting layer 42 and the second electrode 32), and the second pad electrode may be connected to the transparent conductive material layer. In this case, a structure may be achieved in which light can be emitted either through the first light-reflecting layer 41 or through the second light-reflecting layer 42.

[0132] The specifications of each light-emitting element constituting the light-emitting element unit are shown in Table 6 below.

[0133] Second pad electrode Ti / Au Second light-reflecting layer 42 SiO2 / Ta2O5 (14 pairs) Second electrode 32 ITO (thickness: 20 nm) Second compound semiconductor layer 22 p-GaN (thickness: 130 nm) Active layer 23: Multiple quantum well structure (total thickness: 20 nm) Well layer InGaN (Si doped: 2×10 18 cm -3 ) Barrier layer GaN First compound semiconductor layer 21 n-GaN First light-reflecting layer 41 SiO2 / SiN (9 pairs) First pad electrode V / Pt / Au λ0445nm L OR 25 μm θ Y 3 degrees or less θ X 8 degrees L 32AB 50 μm W 32AB 20 μm r 32CD 10 μm L max-Y 25 μm L min-X 6 μm L 51AB 25 μm r 51CD -- R135μm R 91BC 35 μm P X 20 μm θ Y ' 1 degree or less θ X ' 1 degree or less

[0134] In the light emitting elements of Examples 1 and 2, the value of the emission angle in the X direction is large. On the other hand, in the light emitting element unit of Example 4, the plurality of light emitting elements are arranged in the X direction at a short arrangement pitch P X By arranging the light emitting elements in this way, coherence can be given to the light emitting elements, and coupling between the light emitting elements occurs. As a result, the multiple light emitting elements that make up the light emitting element unit behave as if they were a single light emitting element, increasing the "uncertainty of the position where light exists" in the X direction and decreasing the output angle θ in the X direction. X In the case of one light-emitting element, the output angle θ X The output angle in the X direction is 8 degrees, but by arranging four light-emitting elements, for example, X It is possible to keep the temperature drop to less than 0.1 degrees.

[0135] Furthermore, for example, if four light-emitting elements are arranged side by side, the width of the light-emitting element unit in the X direction will be as much as 60 μm. If a single light-emitting element with a width of 60 μm equivalent to such a light-emitting element unit is assumed, a single large current injection region must be formed. However, this would result in uneven current density and an uneven resonator structure of the light-emitting element, making it impossible to maintain coherence across the entire region. On the other hand, in the light-emitting element unit of Example 4, the distance from the second electrode to each portion of the current injection region in each light-emitting element is short, allowing current to be injected uniformly within each light-emitting element. Therefore, it is possible to provide a light-emitting element with a light field spanning a large area and a narrow emission angle, which is not possible with a light-emitting element having a large element region with a width of 60 μm. Furthermore, by individually driving the light-emitting elements constituting the light-emitting element unit, it is possible to selectively irradiate desired locations or areas.

[0136] 14, the second portion 92 of the base surface 90 is flattened along the X and Y directions. On the other hand, in Modification 1 of the light-emitting element unit of Example 4, the partial end view of which is shown in FIG. 15 along the X direction, the second portion 92 of the base surface 90 is recessed toward the second surface 21b of the first compound semiconductor layer 21 along the X and Y directions, similar to Example 3, when the second surface 21b of the first compound semiconductor layer 21 is used as a reference. [Example]

[0137] Example 5 relates to a light-emitting device according to the second aspect of the present disclosure. A schematic partial end view of the light-emitting device of Example 5 is shown in Fig. 16, and the arrangements of the current injection region, current confinement region, and second electrode constituting the light-emitting device of Example 5 are shown in Figs. 17(A), (B), (C), and (D) and Fig. 18(A), and the arrangements of the current injection region and current confinement region are shown in Fig. 18(B). The second electrode is not shown in Fig. 18(B).

[0138] In the light-emitting device of Example 5, the planar shape of the current injection region 51 surrounded by the current confinement region 52 is at least one shape selected from the group consisting of a ring, a ring with a portion cut out, a shape surrounded by curves, a shape surrounded by multiple line segments, and a shape surrounded by curves and line segments (in other words, a shape other than a circle). Here, the planar shape of the current injection region 51 can be a shape consisting of letters or figures. Unlike the light-emitting devices of Examples 1 to 3, the first light-reflecting layer 41 is formed on a flat base surface 90.

[0139] In the example shown in FIG. 17A, the planar shape of the current injection region 51 is annular (ring-shaped), with the inner portion of the annulus being occupied by the current confinement region 52A and the outer portion of the annulus being occupied by the current confinement region 52B. The orthogonal projection image of the current injection region 51 and the current confinement region 52A is included in the orthogonal projection image of the second electrode 32. The orthogonal projection image of the current confinement region 52B is included in the orthogonal projection image of the second electrode 32. The emission angle can be, for example, 5 degrees. The outer diameter, inner diameter, and width of the annular shape are 12 μm, 4 μm, and 4 μm, respectively. The outer diameter, inner diameter, and width of the partially cut-out annular shape described below are also 12 μm, 4 μm, and 4 μm, and the width of the line segment is also 4 μm.

[0140] 17(B), the planar shape of the current injection region 51 is a partially cut-out ring (shaped like the letter "C"). The current injection region 51 is surrounded by the current confinement region 52. The orthogonal projection image of the second electrode 32 includes the orthogonal projection image of the current injection region 51. Furthermore, the orthogonal projection image of the current confinement region 52 includes the orthogonal projection image of the second electrode 32.

[0141] In the examples shown in FIGS. 17C and 17D and FIG. 18A, the planar shape of the current injection region 51 is a shape surrounded by curves and line segments. Specifically, in the examples shown in FIGS. 17C and 17D, the shape is a combination of a ring shape and line segments. The inner part of the ring shape of the current injection region 51 is occupied by the current confinement region 52A, and the outer part of the ring shape is occupied by the current confinement region 52B. The orthogonal projection image of the second electrode 32 includes the orthogonal projection image of the current injection region 51, the current confinement region 52A, and the line segments. The orthogonal projection image of the second electrode 32 includes the orthogonal projection image of the current confinement region 52B. On the other hand, in the example shown in FIG. 18A, the shape is a combination of a partially cut-out ring shape and line segments. The current injection region 51 is surrounded by the current confinement region 52. The orthogonal projection image of the current injection region 51 is included in the orthogonal projection image of the second electrode 32. Furthermore, the orthogonal projection image of the current confinement region 52 includes the orthogonal projection image of the second electrode 32 .

[0142] 18(B), the planar shape of current injection region 51 is a combination of multiple rings. The inner portion of the ring is occupied by current confinement region 52A, and the outer portion of the ring is occupied by current confinement region 52B. The orthogonal projection image of the second electrode (not shown) includes the orthogonal projection image of current injection region 51 and current confinement region 52A. Furthermore, the orthogonal projection image of current confinement region 52B includes the orthogonal projection image of the second electrode.

[0143] 19A, 19B, 19C, 19D, and 19E show the planar shape of the current injection region 51 constituting the light-emitting device of Example 5, which may be the letter "A" (see FIG. 19A), "E" (see FIG. 19B), or "T" (see FIG. 19C), or a shape such as a square (see FIG. 19D), or a hexagon (see FIG. 19E). The second electrode and the current confinement region are not shown in these figures.

[0144] The configuration and structure of the light-emitting device in Example 5 can be the same as the configuration and structure of the light-emitting device described in Examples 1 and 2, except for the difference in the structure of the first light reflecting layer 41, and therefore detailed description thereof will be omitted. Note that the configuration and structure of the light-emitting device in Example 5 can also be the same as the configuration and structure of the light-emitting device having the first light reflecting layer 41 described in Examples 1 to 3.

[0145] In the light-emitting device of Example 5, the planar shape of the current injection region surrounded by the current constriction region is annular, for example. By using an appropriate optical system, specifically, for example, by forming a mirror (concave mirror) having a lens-like structure with a concave cross section and arranging the light-emitting device on the main axis of the concave mirror, it becomes possible to project and view the light emitted from the light-emitting device as figures or characters, and it becomes possible to emit and project a light beam with a complex shape. Furthermore, by combining multiple light-emitting devices, it becomes possible to display and emit character strings, multiple figures, or a combination of characters and figures. Furthermore, for example, if the planar shape of the current injection region is annular, a beam with a similar narrow emission angle can be obtained with less current and power than when the planar shape of the current injection region is circular. This ultimately reduces heat generation and improves reliability. [Example]

[0146] Example 6 is a modification of Examples 1 to 5. In Examples 1 to 5, the stacked structure 20 is made of a GaN-based compound semiconductor. On the other hand, in Example 6, the stacked structure 20 is made of an InP-based compound semiconductor or a GaAs-based compound semiconductor. As an example, the specifications of the light-emitting device in the light-emitting device having the configuration of Example 2 shown in FIG. 9 (where the stacked structure 20 is made of an InP-based compound semiconductor) are shown in Table 7 below. Furthermore, the specifications of the light-emitting device in the light-emitting device having the configuration of Example 2 shown in FIG. 9 (where the stacked structure 20 is made of a GaAs-based compound semiconductor) are shown in Table 8 below.

[0147] Second light-reflecting layer 42 SiO2 / Ta2O5 (8 pairs) or, AlInGaAsP layer and AlInGaAsSb layer 2nd electrode 32 Ti / Pt / Au Second compound semiconductor layer 22 p-InP active layer 23 Well layer: AlGaInAs (multiple quantum well structure) (λ0:1.0μm~1.6μm) or, InGaAsP (multiple quantum well structure) (λ0:1.0μm~1.6μm) or, InAs quantum dots (λ0: 1.2 μm to 1.8 μm) Barrier layer GaInAsP or, AlGaInAs First compound semiconductor layer 21 n-InP First light-reflecting layer 41 SiO2 / SiN (10 pairs) Substrate: Undoped InP substrate, or, Doping amount 1×10 18 cm -3 The following InP substrates λ01.4μm L OR 10 μm θ Y 10 degrees or less θ X 30 degrees L 32AB 50 μm W 32AB 20 μm r 32CD 10 μm L max-Y 25 μm L min-X 6 μm L 51AB 25 μm r 51CD 5 μm R115μm R 91BC 15 μm P X 20 μm θ Y' Below 1 degree θ X ' Below 1 degree

[0148] Table 8 Second light reflecting layer 42 p-AlGaAs (28 pages) あるいは、 SiO2 / Ta2O5(11.5ペア) Second electrode 32 Ti / Pt / Au Second compound semiconductor layer 22 p-GaAs Active layer 23 GaInAs (multi-quantum well structure) (λ0: 0.85μm~1.2μm) あるいは、 GaInNAs (Multiple Quantum Ichiro Structure) (λ0:1.2μm~1.5μm) あるいは、 InAs Quantum ドット (λ0:1.2μm~1.5μm) バリアGaAs First compound semiconductor layer 21 n-GaAs 1st light reflective layer 41 SiO2 / SiN (10ペア) λ01.4μm L OR 10μm θ Y Below 10 degrees θ X 31 degrees L 32AB 50μm W 32AB 20μm r 32CD 10μm L max-Y 25μm L min-X 6μm L 51AB 25μm r 51CD 5μm R115μm R 91BC 15μm P X 20μm θ Y ' Below 1 degree θX ' 1 degree or less

[0149] The light-emitting element of Example 6 can have the same configuration and structure as the light-emitting elements of Examples 1 to 3 and Example 5, except that the configuration of the laminated structure is different, and the light-emitting element unit using the light-emitting element of Example 6 can have the same configuration and structure as the light-emitting element unit of Example 4. [Example]

[0150] The seventh embodiment is a modification of the first to sixth embodiments.

[0151] Incidentally, the cavity length L in the laminated structure formed by two DBR layers and the laminated structure formed therebetween is OR is the equivalent refractive index of the entire laminate structure, n eq When the wavelength of the laser light to be emitted from the surface-emitting laser element (light-emitting element) is λ0, L=(m λ0) / (2 n eq ) Here, m is a positive integer. In a surface-emitting laser element (light-emitting element), the wavelength that can be oscillated is expressed as OR The individual oscillation modes that can oscillate are called longitudinal modes. Among the longitudinal modes, those that match the gain spectrum determined by the active layer can oscillate as lasers. The spacing Δλ between longitudinal modes is determined by the effective refractive index n eff When λ0 2 / (2n eff L) That is, the resonator length L OR The longer the cavity length L, the narrower the longitudinal mode spacing Δλ. OR When the effective refractive index n eq and the effective refractive index n eff When the oscillation wavelength is λ0, the following relationship exists between

[0152] n eff =n eq -λ0·(dneq / dλ0)

[0153] Here, when the laminated structure is made of GaAs-based compound semiconductor layers, the cavity length L OR is usually as short as 1 μm or less, and the longitudinal mode laser light emitted from the surface-emitting laser element is of one type (one wavelength) (see the conceptual diagram in FIG. 29A). Therefore, it is possible to accurately control the oscillation wavelength of the longitudinal mode laser light emitted from the surface-emitting laser element. On the other hand, when the stacked structure is made of GaN-based compound semiconductor layers, the cavity length L OR is usually several times longer than the wavelength of the laser light emitted from the surface-emitting laser element. Therefore, the laser light that can be emitted from the surface-emitting laser element will have multiple types of longitudinal modes (see the conceptual diagram in FIG. 29B), making it difficult to accurately control the oscillation wavelength of the laser light that can be emitted from the surface-emitting laser element.

[0154] 20 is a schematic partial cross-sectional view of the light-emitting device 10C of Example 7, or the light-emitting devices of Examples 8 and 9 described below, in the stacked structure 20 including the second electrode 32, at least two light-absorbing material layers 26, preferably at least four light-absorbing material layers 26, and specifically, 20 light-absorbing material layers 26 in Example 7, are formed parallel to a virtual plane (XY virtual plane) occupied by the active layer 23. To simplify the drawing, only one light-absorbing material layer 26 is shown in the drawing.

[0155] In Example 7, the oscillation wavelength (desired oscillation wavelength emitted from the light emitting element) λ0 is 450 nm. The 20 light absorbing material layers 26 are made of a compound semiconductor material having a band gap narrower than that of the compound semiconductor constituting the stacked structure 20, specifically, n-In. 0.2 Ga 0.8 N and is formed inside the first compound semiconductor layer 21. The thickness of the light absorbing material layer 26 is λ0 / (4·n eq ) or less, specifically, 3 nm. The light absorption coefficient of the light absorption material layer 26 is at least twice the light absorption coefficient of the first compound semiconductor layer 21 made of an n-GaN layer, specifically, 1×10 3 It's double.

[0156] The light absorbing material layer 26 is located at the minimum amplitude portion of the standing wave of light formed inside the laminated structure, and the active layer 23 is located at the maximum amplitude portion of the standing wave of light formed inside the laminated structure. The distance between the center of the active layer 23 in the thickness direction and the center of the light absorbing material layer 26 adjacent to the active layer 23 in the thickness direction is 46.5 nm. Furthermore, the equivalent refractive index of the entire two light absorbing material layers 26 and the portion of the laminated structure located between the light absorbing material layers 26 (specifically, the first compound semiconductor layer 21 in Example 7) is set to n eq , the distance between the light absorbing material layers 26 is L Abs When 0.9×{(m λ0) / (2 n eq )}≦L Abs ≦1.1×{(m λ0) / (2 n eq )} Here, m is 1 or any integer equal to or greater than 1. However, in Example 7, m=1. Therefore, the distance between adjacent light absorbing material layers 26 is set to be: 0.9×{λ0 / (2·n eq )}≦L Abs ≦1.1×{λ0 / (2·n eq )} The equivalent refractive index n eq The value of is specifically 2.42, and when m=1, specifically, L Abs =1×450 / (2×2.42) =93.0nm In some of the 20 light absorbing material layers 26, m may be any integer of 2 or more.

[0157] In manufacturing the light-emitting device of Example 7, the stacked structure 20 is formed in the same step as [Step-100] of Example 1, but at this time, 20 light-absorbing material layers 26 are also formed inside the first compound semiconductor layer 21. Except for this point, the light-emitting device of Example 7 can be manufactured based on the same method as the light-emitting device of Example 5.

[0158] When multiple longitudinal modes occur within the gain spectrum determined by the active layer 23, this is schematically shown in FIG. 28. Note that FIG. 28 illustrates two longitudinal modes, longitudinal mode A and longitudinal mode B. In this case, the light-absorbing material layer 26 is positioned in the minimum amplitude portion of longitudinal mode A but not in the minimum amplitude portion of longitudinal mode B. In this case, the mode loss of longitudinal mode A is minimized, but the mode loss of longitudinal mode B is large. In FIG. 28, the mode loss of longitudinal mode B is schematically shown by a solid line. Therefore, longitudinal mode A oscillates more easily than longitudinal mode B. Therefore, by using this structure, i.e., by controlling the position and period of the light-absorbing material layer 26, a specific longitudinal mode can be stabilized and made to oscillate more easily. On the other hand, the mode loss for other undesired longitudinal modes can be increased, thereby suppressing oscillation of other undesired longitudinal modes.

[0159] As described above, in the light-emitting device of Example 7, at least two light-absorbing material layers are formed inside the laminated structure, so that it is possible to suppress oscillation of laser light of an undesired longitudinal mode among the multiple types of longitudinal modes of laser light that can be emitted from the surface-emitting laser element. As a result, it is possible to accurately control the oscillation wavelength of the emitted laser light. Moreover, since the light-emitting device of Example 7 has the first portion, it is possible to reliably suppress the occurrence of diffraction loss. [Example]

[0160] Example 8 is a modification of Example 7. In Example 7, the light absorbing material layers 26 are made of a compound semiconductor material having a band gap narrower than that of the compound semiconductor constituting the stacked structure 20. On the other hand, in Example 8, the ten light absorbing material layers 26 are made of a compound semiconductor material doped with impurities, specifically, 1×10 19 / cm 3 The active layer 23 was made of a compound semiconductor material (specifically, n-GaN:Si) having an impurity concentration (impurity: Si). In Example 8, the oscillation wavelength λ0 was set to 515 nm. The composition of the active layer 23 was In. 0.3 Ga 0.7 In Example 8, m=1 and L Abs The value of m is 107 nm, the distance between the center of the active layer 23 in the thickness direction and the center of the light absorbing material layer 26 adjacent to the active layer 23 in the thickness direction is 53.5 nm, and the thickness of the light absorbing material layer 26 is 3 nm. Except for the above points, the configuration and structure of the light absorbing device of Example 8 can be similar to the configuration and structure of the light absorbing material layer 26 of Example 7, and therefore detailed description will be omitted. Note that, in some of the 10 light absorbing material layers 26, m can be any integer equal to or greater than 2. [Example]

[0161] Example 9 is also a modification of Example 7. In Example 9, five light absorbing material layers (for convenience, referred to as "first light absorbing material layers") are formed with the same structure as the light absorbing material layer 26 of Example 7, that is, n-In 0.3 Ga 0.7 Furthermore, in Example 9, one light absorbing material layer (for convenience, referred to as the "second light absorbing material layer") was made of a transparent conductive material. Specifically, the second light absorbing material layer also served as the second electrode 32 made of ITO. In Example 9, the oscillation wavelength λ0 was set to 450 nm. Furthermore, m=1 and 2. When m=1, L Abs The value of is 93.0 nm, the distance between the center of the active layer 23 in the thickness direction and the center of the first light absorbing material layer adjacent to the active layer 23 in the thickness direction is 46.5 nm, and the thickness of the five first light absorbing material layers is 3 nm. 0.9×{λ0 / (2·n eq )}≦L Abs ≦1.1×{λ0 / (2·n eq )} The first light absorbing material layer and the second light absorbing material layer adjacent to the active layer 23 satisfy m=2. 0.9×{(2·λ0) / (2·n eq )}≦L Abs ≦1.1×{(2·λ0) / (2·n eq )} The light absorption coefficient of the single second light absorbing material layer, which also serves as the second electrode 32, is 2000 cm -1 , and the thickness is 30 nm, and the distance from the active layer 23 to the second light absorbing material layer is 139.5 nm. Except for the above points, the configuration and structure of the light emitting device of Example 9 can be the same as the configuration and structure of the light absorbing material layer of Example 7, so a detailed description will be omitted. Note that, in some of the five first light absorbing material layers, m can be any integer equal to or greater than 2. Note that, unlike Example 7, the number of light absorbing material layers 26 can also be 1. In this case, too, the positional relationship between the second light absorbing material layer that also serves as the second electrode 32 and the light absorbing material layer 26 must satisfy the following formula: 0.9×{(m λ0) / (2 n eq )}≦L Abs ≦1.1×{(m λ0) / (2 n eq )} [Example]

[0162] Example 10 relates to an electronic device or a light-emitting device. The electronic device or light-emitting device of Example 10 includes the light-emitting element of Examples 1 to 3 and Example 5, or the light-emitting element unit of Example 4. Specifically, the light-emitting element of Examples 1 to 3 and Example 5, and the light-emitting element unit of Example 4 can be incorporated into electronic devices such as various display devices such as projectors, television receivers, and monitors, pixels that constitute display devices, indoor and outdoor lighting, laser pointers, levels, and distance measuring devices that use lasers. The electronic device itself may have a known configuration and structure.

[0163] Alternatively, a light emitting device (or lighting device) can be configured using the light emitting elements of Examples 1 to 3 and Example 5 and the light emitting element unit of Example 4 described above. For example, as shown in FIG. 17A, a light emitting device (specifically, a headlight, for example) having a current injection region 51 with an annular (ring-shaped) planar shape can be mounted on various moving objects such as vehicles including automobiles, motorcycles, and bicycles. For example, the outer diameter, inner diameter, and width of the annular shape can be 24 μm, 12 μm, and 6 μm. The cross-sectional shape of the emitted light immediately after being emitted from the light emitting element is annular, but becomes circular or the like at a sufficient distance from the light emitting element, thereby enabling a high-quality light beam to be obtained.

[0164] Alternatively, it can be used as a light emitting device (or lighting device) in devices such as a light source unit for a line sensor, a light source unit for a multi-layered two-dimensional line sensor, a Li-Hi light source unit that is faster and can cover a wider area, or a laser processing light source unit that can process a wider area.Furthermore, it can be incorporated into various display devices.The light emitting device, lighting device, and display device themselves may have a known configuration and structure.

[0165] The oscillation wavelength (light emission wavelength) λ0 of the light emitting element may be, for example, 400 nm to 500 nm, or if a wavelength conversion material layer (color conversion material layer) described later is provided, light of a desired color can be emitted.

[0166] The light emitting device (or lighting device) of Example 10 has a smaller (narrower) emission angle than a commonly used edge-emitting laser element (or surface-emitting laser element). Furthermore, a light beam with a narrow emission angle that spreads around the periphery of the light emitting device (or lighting device) can be obtained without an external optical system (external optical components) (or with only simple optical components), which allows the entire device to be made lighter, less expensive, and more reliable.

[0167] Furthermore, a light-emitting device (or lighting device) may be used as a light source to illuminate a desired object, part, location, etc., using, for example, an optical fiber. In this case, the light emitted from the light-emitting device can be efficiently coupled to the optical fiber, thereby reducing power consumption and achieving a longer lifespan.

[0168] The electronic device or light-emitting device of Example 10 and the sensing device of Example 11 described later may include multiple types of the light-emitting elements of Example 5. That is, the electronic device, light-emitting device, or sensing device may be configured by mixing light-emitting elements whose planar shape of the current injection region described in Example 5 is formed of at least one shape selected from the group consisting of a ring, a ring with a partial cutout, a shape surrounded by curves, a shape surrounded by multiple line segments, and a shape surrounded by curves and line segments. The irradiation pattern is changed by individually driving each light-emitting element as appropriate. [Example]

[0169] An eleventh embodiment relates to a sensing device. The sensing device of the eleventh embodiment includes: A light emitting device including the light emitting element of Example 1 to Example 3 or Example 5, or the light emitting element unit of Example 4, and a light receiving device that receives the light emitted from the light emitting device; The sensing device itself may have a known configuration and structure.

[0170] A specific example of a sensing device is a LIDAR (Light Detection and Ranging). Alternatively, the device can be used as a light emitting device that emits structured light in a three-dimensional sensing device, which is a method for measuring the distance to a subject or measuring the three-dimensional shape of the subject in a non-contact manner. For example, the structured light can be emitted based on infrared light and irradiated onto the subject. Examples of structured light include a line-and-space pattern, a grid pattern, and a dot pattern. These patterns can be emitted from a light emitting device equipped with the light emitting element of Examples 1 to 3 and Example 5, or the light emitting element unit of Example 4. Alternatively, if a light-emitting element whose cross-sectional shape of emitted light is a "rod-like" or "I-like" shape extending in the Y direction as described in Example 1 is used as the light-emitting device of a sensing device, and the light-emitting device is attached to the location to be sensed or to various moving objects such as vehicles including automobiles, motorcycles, and bicycles with the Y direction as the vertical direction, it becomes possible to illuminate a wide area in the horizontal direction and sense a wide area in the horizontal direction. Alternatively, examples of sensing devices include portable image displays, communication devices, and smartphones. [Example]

[0171] A twelfth embodiment relates to a communication device. The communication device of the twelfth embodiment includes: A light emitting device including a plurality of types of light emitting elements according to the fifth embodiment, and a light receiving device that receives the light emitted from the light emitting device; It has.

[0172] Here, the light-emitting device including a plurality of types of light-emitting elements of Example 5 refers to a light-emitting device including a mixture of light-emitting elements whose planar shape of the current injection region described in Example 5 is formed of at least one type of shape selected from the group consisting of a ring, a ring with a portion cut out, a shape surrounded by curves, a shape surrounded by multiple line segments, and a shape surrounded by curves and line segments. In other words, it refers to a light-emitting device equipped with a plurality of atypical light sources (a plurality of light-emitting elements whose cross-sectional shapes of emitted light are different).

[0173] A DOE (Diffractive Optical Element) is disposed between the light-emitting device and the light-receiving device. Furthermore, optical elements such as lenses may be disposed. The irradiation pattern is changed by individually and appropriately driving each light-emitting element. The light reaching the light-receiving device varies depending on the configuration, type, shape, and performance of an external optical system (external optical component) such as a DOE, its relative position with respect to the light-emitting device, the light-emitting pattern of the multiple types of light-emitting elements constituting the light-emitting device, the cross-sectional shape of the light emitted from the light-emitting device, the driving conditions of the light-emitting device and the light-emitting elements, and which of the multiple light-emitting elements in the light-emitting device is used to acquire the blinking (flashing) signal (hereinafter, these are collectively referred to as “parameters”). When the light emitted from the light-emitting device reaches the light-receiving device, if the parameters are unknown, it is impossible to know how the light emitted from the light-emitting device will change. Therefore, the communication device of Example 12 can be used to configure a type of cryptographic communication system using all or part of these parameters as a composite key.

[0174] That is, in normal space communication (or visible light communication), information is given (encoded) in the blinking of a light source and transmitted over a long distance. However, in this case, if a light-receiving element is placed in the area where the light is irradiated, the information can be obtained. That is, it can be easily intercepted. On the other hand, in the communication device of Example 12, a third party who does not know the above parameters cannot know the information contained in the blinking of the light-emitting element. Therefore, these parameters can be used as a compound key for encrypted transmission and communication systems, and the communication device of Example 12 can be used to transmit information over a long distance more securely than when a single light-emitting element is simply blinked. That is, the blinking of a specific pattern can be encrypted and used for space transmission, and private communication can be performed in a public space using visible light space communication, etc. Furthermore, when transmitting multiple patterns over a long distance, it can be applied to communication in which unique information is carried in each pattern, similar to PAM4 in optical communication.

[0175] Although the present disclosure has been described above based on preferred embodiments, the present disclosure is not limited to these embodiments. The configurations and structures of the light-emitting elements described in the embodiments are merely illustrative and can be modified as appropriate, and the manufacturing method of the light-emitting element can also be modified as appropriate. In some cases, by appropriately selecting the bonding layer and support substrate, a surface-emitting laser element can be formed that emits light from the second surface of the second compound semiconductor layer through the second optical reflection layer. In other cases, a through-hole extending to the first compound semiconductor layer can be formed in a region of the second compound semiconductor layer and active layer that does not affect the light emission, and a first electrode insulated from the second compound semiconductor layer and active layer can be formed in this through-hole. The first optical reflection layer may extend to the second portion of the base surface. That is, the first optical reflection layer on the base surface may be formed as a so-called solid film. In this case, a through-hole can be formed in the first optical reflection layer extending to the second portion of the base surface, and a first electrode connected to the first compound semiconductor layer can be formed in this through-hole. The base surface can also be formed by providing a sacrificial layer using a nanoimprint method. Except for Example 5, the first light reflecting layer was formed on the convex portions of the base surface, but in each example, it may be formed on a flat base surface.

[0176] In order to control the polarization state of light emitted from the light emitting element, the second electrode may be formed with a plurality of grooves extending in one direction (X direction or Y direction).

[0177] A wavelength conversion material layer (color conversion material layer) may be provided in the region where the light of the light-emitting element is emitted. In this case, white light may be emitted via the wavelength conversion material layer (color conversion material layer). Specifically, when the light emitted from the active layer is emitted to the outside via the first light reflecting layer, the wavelength conversion material layer (color conversion material layer) may be formed on the light-emitting side of the first light reflecting layer. When the light emitted from the active layer is emitted to the outside via the second light reflecting layer, the wavelength conversion material layer (color conversion material layer) may be formed on the light-emitting side of the second light reflecting layer.

[0178] When blue light is emitted from the light emitting layer, the following configuration can be adopted to make it possible to emit white light via the wavelength converting material layer. [A] By using a wavelength converting material layer that converts blue light emitted from the light emitting layer into yellow light, white light that is a mixture of blue and yellow light is obtained as light emitted from the wavelength converting material layer. [B] By using a wavelength converting material layer that converts blue light emitted from the light emitting layer into orange light, white light that is a mixture of blue and orange is obtained as light emitted from the wavelength converting material layer. [C] By using a wavelength converting material layer that converts blue light emitted from the light-emitting layer into green light and a wavelength converting material layer that converts it into red light, white light that is a mixture of blue, green, and red is obtained as light emitted from the wavelength converting material layer.

[0179] Alternatively, when ultraviolet light is emitted from the light emitting layer, the following configuration can be adopted to emit white light via the wavelength converting material layer. [D] By using a wavelength converting material layer that converts the ultraviolet light emitted from the light-emitting layer into blue light and a wavelength converting material layer that converts it into yellow light, white light that is a mixture of blue and yellow is obtained as the light emitted from the wavelength converting material layer. [E] By using a wavelength converting material layer that converts the ultraviolet light emitted from the light-emitting layer into blue light and a wavelength converting material layer that converts it into orange light, white light that is a mixture of blue and orange is obtained as the light emitted from the wavelength converting material layer. [F] By using a wavelength converting material layer that converts the ultraviolet light emitted from the light-emitting layer into blue light, a wavelength converting material layer that converts it into green light, and a wavelength converting material layer that converts it into red light, white light that is a mixture of blue, green, and red is obtained as the light emitted from the wavelength converting material layer.

[0180] Here, examples of wavelength conversion materials that are excited by blue light and emit red light include red-emitting phosphor particles, more specifically, (ME:Eu)S [where "ME" means at least one atom selected from the group consisting of Ca, Sr, and Ba, and the same applies hereinafter], (M:Sm) x (Si, Al) 12 (O,N) 16 [Note that "M" refers to at least one atom selected from the group consisting of Li, Mg, and Ca, and the same applies hereinafter], ME2Si5N8:Eu, (Ca:Eu)SiN2, and (Ca:Eu)AlSiN3 are examples of wavelength conversion materials that are excited by blue light and emit green light, and specifically, green-emitting phosphor particles, more specifically, (ME:Eu)Ga2S4 and (M:RE) x (Si, Al) 12 (O,N) 16 [wherein "RE" means Tb and Yb], (M:Tb) x (Si, Al) 12 (O,N) 16 , (M:Yb) x (Si, Al) 12 (O,N) 16 , Si 6-Z Al Z O Z N 8-Z:Eu can be cited. Furthermore, as a wavelength converting material that is excited by blue light and emits yellow light, specifically, yellow light-emitting phosphor particles, more specifically, YAG (yttrium aluminum garnet) phosphor particles can be cited. The wavelength converting material may be one type, or two or more types may be mixed and used. Furthermore, by using a mixture of two or more types of wavelength converting materials, it is possible to configure the wavelength converting material mixture to emit light of a color other than yellow, green, and red. Specifically, for example, a configuration that emits cyan light may be used, in which case green light-emitting phosphor particles (e.g., LaPO4:Ce,Tb,BaMgAl 10 O 17 :Eu,Mn,Zn2SiO4:Mn,MgAl 11 O 19 :Ce,Tb,Y2SiO5:Ce,Tb,MgAl 11 O 19 :CE,Tb,Mn) and blue-emitting phosphor particles (e.g., BaMgAl 10 O 17 :Eu, BaMg2Al 16 O 27 :Eu, Sr2P2O7:Eu, Sr5(PO4)3Cl:Eu, (Sr,Ca,Ba,Mg)5(PO4)3Cl:Eu, CaWO4, CaWO4:Pb) may be used.

[0181] In addition, wavelength conversion materials that are excited by ultraviolet light and emit red light include red-emitting phosphor particles, more specifically, Y2O3:Eu, YVO4:Eu, Y(P,V)O4:Eu, 3.5MgO·0.5MgF2·Ge2:Mn, CaSiO3:Pb,Mn, and Mg6AsO 11 :Mn, (Sr,Mg)3(PO4)3:Sn, La2O2S:Eu, and Y2O2S:Eu. Specific examples of wavelength conversion materials that are excited by ultraviolet light and emit green light include green-emitting phosphor particles, more specifically, LaPO4:Ce,Tb, and BaMgAl. 10 O 17 :Eu,Mn,Zn2SiO4:Mn,MgAl 11 O 19:Ce,Tb,Y2SiO5:Ce,Tb,MgAl 11 O 19 : Ce, Tb, Mn, Si 6-Z Al Z O Z N 8-Z Furthermore, examples of wavelength conversion materials that are excited by ultraviolet light and emit blue light include blue light-emitting phosphor particles, more specifically BaMgAl 10 O 17 :Eu, BaMg2Al 16 O 27 Examples of wavelength converting materials that are excited by ultraviolet light and emit yellow light include yellow-emitting phosphor particles, more specifically, YAG-based phosphor particles. The wavelength converting material may be one type, or two or more types may be mixed. Furthermore, by using a mixture of two or more types of wavelength converting materials, it is possible to configure the wavelength converting material mixture to emit light of a color other than yellow, green, or red. Specifically, a configuration that emits cyan light may be used, in which case a mixture of the above-mentioned green-emitting phosphor particles and blue-emitting phosphor particles may be used.

[0182] However, wavelength conversion materials (color conversion materials) are not limited to phosphor particles, and examples include luminescent particles that use quantum well structures such as a two-dimensional quantum well structure, a one-dimensional quantum well structure (quantum wire), and a zero-dimensional quantum well structure (quantum dot) that localize the carrier wave function and use the quantum effect in indirect transition silicon-based materials to efficiently convert carriers into light, just like in direct transition materials; and it is known that rare earth atoms added to semiconductor materials emit sharp light due to intrashell transitions, and luminescent particles that use such technology can also be mentioned.

[0183] As mentioned above, quantum dots can be used as wavelength conversion materials (color conversion materials). As the size (diameter) of a quantum dot decreases, the band gap energy increases, and the wavelength of light emitted from the quantum dot decreases. That is, the smaller the quantum dot, the shorter the wavelength of light it emits (light on the bluer side), and the larger the quantum dot, the longer the wavelength of light it emits (light on the redr side). Therefore, by using the same material to compose the quantum dot and adjusting the size of the quantum dot, quantum dots that emit light with a desired wavelength (color conversion to a desired color) can be obtained. Specifically, it is preferable that the quantum dot have a core-shell structure. Examples of materials that can be used to form quantum dots include, but are not limited to, Si; Se; chalcopyrite compounds such as CIGS (CuInGaSe), CIS (CuInSe2), CuInS2, CuAlS2, CuAlSe2, CuGaS2, CuGaSe2, AgAlS2, AgAlSe2, AgInS2, and AgInSe2; perovskite materials; III-V compounds such as GaAs, GaP, InP, InAs, InGaAs, AlGaAs, InGaP, AlGaInP, InGaAsP, and GaN; CdSe, CdSeS, CdS, CdTe, In2Se3, In2S3, Bi2Se3, Bi2S3, ZnSe, ZnTe, ZnS, HgTe, HgS, PbSe, PbS, and TiO2.

[0184] The present disclosure can also be configured as follows. [A01] Light-emitting element: First embodiment a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light-reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; When the thickness-direction axis of the laminated structure passing through the center of the current injection region surrounded by the current constriction region is defined as the Z-axis, the direction perpendicular to the Z-axis is defined as the X-direction, and the direction perpendicular to the X-direction and Z-axis is defined as the Y-direction, the current injection region is a light-emitting element having an elongated planar shape with its longitudinal direction extending in the Y-direction. [A02] The width of the current injection region along the Y direction is L max-Y , the width along the X direction is L min-X When L max-Y / L min-X ≧3 The light-emitting element according to [A01], which satisfies the following. [A03] The first light reflecting layer has a convex shape extending in a direction away from the active layer, The light-emitting device according to [A01] or [A02], wherein the second light-reflecting layer has a flat shape. [A04] The light-emitting device according to any one of [A01] to [A03], wherein the planar shape of the first light-reflecting layer is similar to the planar shape of the current injection region. [A05] The light-emitting device according to any one of [A01] to [A04], wherein the light emission angle in the YZ virtual plane is 2 degrees or less. [A06] The light-emitting device according to any one of [A01] to [A05], wherein the current injection region has an elliptical planar shape. [A07] The light-emitting device according to any one of [A01] to [A05], wherein the current injection region has a rectangular planar shape. [A08] The light-emitting device according to [A07], wherein an end face of the current injection region including a side parallel to the X direction is in contact with a layer in which the first dielectric layer and the second dielectric layer are alternately arranged in the Y direction. [A09] The light-emitting device according to any one of [A06] to [A08], wherein the side of the current injection region parallel to the Y direction is formed by a line segment or a curved line. [A10] Light-emitting element: second embodiment a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light-reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; A light-emitting element in which the planar shape of the current injection region surrounded by the current confinement region is at least one type of shape selected from the group consisting of a ring, a ring with a portion cut out, a shape surrounded by curves, a shape surrounded by multiple line segments, and a shape surrounded by curves and line segments. [A11] The light-emitting device according to [A10], wherein the planar shape of the current injection region is formed by a character or a graphic. [A12] The light-emitting device according to any one of [A01] to [C11], wherein the stacked structure is made of at least one material selected from the group consisting of GaN-based compound semiconductors, InP-based compound semiconductors, and GaAs-based compound semiconductors. [A13] A light-emitting device according to any one of [A01] to [A12], wherein a compound semiconductor substrate is disposed between the first surface of the first compound semiconductor layer and the first light-reflecting layer, and the base surface is composed of the surface of the compound semiconductor substrate. [A14] The light-emitting element according to any one of [A01] to [A12], wherein a base material is disposed between the first surface of the first compound semiconductor layer and the first light-reflecting layer, or alternatively, a compound semiconductor substrate and a base material are disposed between the first surface of the first compound semiconductor layer and the first light-reflecting layer, and the base surface is constituted by the surface of the base material. [A15] The light-emitting element according to [A14], wherein the material constituting the substrate is at least one material selected from the group consisting of transparent dielectric materials such as TiO2, Ta2O5, SiO2, silicone-based resins, and epoxy-based resins. [A16] The first light reflecting layer is formed on a base surface located on the first surface side of the first compound semiconductor layer, The light-emitting device according to any one of [A01] to [A15], wherein the base surface is uneven and differentiable. [A17] The light-emitting device according to [A16], wherein the base surface is smooth. [A18] The light-emitting element according to [A16] or [A17], wherein the first portion of the base surface on which the first light-reflecting layer is formed has an upwardly convex shape when the second surface of the first compound semiconductor layer is used as a reference. [A19] The light-emitting device according to [A18], wherein the second portion of the base surface occupying the peripheral region has a downwardly convex shape when the second surface of the first compound semiconductor layer is taken as a reference. [A20] A light-emitting element according to any one of [A16] to [A19], wherein the shape (figure) drawn by the first part of the base surface when the base surface is cut along an imaginary plane including the stacking direction of the stacked structure is a part of a circle or a part of a parabola. [A21] The light-emitting device according to any one of [A16] to [A20], wherein the first surface of the first compound semiconductor layer constitutes a base surface. [A22] The light-emitting device according to any one of [A16] to [A21], wherein a first light-reflecting layer is formed on the base surface. [A23] A light-emitting element according to any one of [A01] to [A22], wherein at least two light-absorbing material layers are formed in the stacked structure including the second electrode parallel to a virtual plane occupied by the active layer. [A24] The light-emitting device according to [A23], wherein at least four light-absorbing material layers are formed. [A25] The oscillation wavelength is λ0, the equivalent refractive index of the two light-absorbing material layers and the laminated structure located between the light-absorbing material layers is n eq , the distance between the light-absorbing material layers is L Abs When 0.9×{(m λ0) / (2 neq )}≦L Abs ≦1.1×{(m λ0) / (2 n eq )} The light-emitting element according to [A23] or [A24], which satisfies the following. Here, m is 1 or any integer of 2 or more including 1. [A26] The thickness of the light-absorbing material layer is λ0 / (4·n eq The light-emitting element according to any one of [A23] to [A25], wherein: [A27] The light-emitting device according to any one of [A23] to [A26], wherein the light-absorbing material layer is located in a minimum amplitude portion of a standing wave of light formed inside the laminated structure. [A28] The light-emitting device according to any one of [A23] to [A27], wherein the active layer is located in a maximum amplitude portion of a standing wave of light formed inside the laminated structure. [A29] The light-emitting device according to any one of [A23] to [A28], wherein the light-absorbing material layer has a light absorption coefficient at least twice as high as the light absorption coefficient of the compound semiconductor constituting the laminate structure. [A30] The light-emitting device according to any one of [A23] to [A29], wherein the light-absorbing material layer is composed of at least one material selected from the group consisting of a compound semiconductor material having a narrower band gap than the compound semiconductor constituting the stacked structure, a compound semiconductor material doped with impurities, a transparent conductive material, and a light-reflecting layer-constituting material having light-absorbing properties. [B01]《Light-emitting element unit》 A light-emitting element unit consisting of a plurality of light-emitting elements, Each light-emitting element is a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light-reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; When an axis in the thickness direction of the laminated structure passing through the center of the current injection region surrounded by the current confinement region is defined as a Z axis, a direction perpendicular to the Z axis is defined as an X direction, and a direction perpendicular to the X direction and the Z axis is defined as a Y direction, the current injection region has an elongated planar shape whose longitudinal direction extends in the Y direction, The light-emitting element unit includes a plurality of light-emitting elements arranged at intervals in the X direction. [B02] The width of the current injection region in each light-emitting element along the Y direction is L max-Y , the width along the X direction is L min-X When L max-Y / L min-X ≧3 Satisfied, The arrangement pitch of the multiple light emitting elements along the X direction is P X When P X / L min-X ≧1.5 The light-emitting element unit according to [B01], which satisfies the above. [B03] In the entire light-emitting element unit, The light emission angle in the YZ virtual plane is 2 degrees or less, The light-emitting element unit according to [B01] or [B02], wherein the light emission angle in the XZ virtual plane is 0.1 degrees or less. [B04] The first electrode is common to a plurality of light-emitting elements, The light-emitting element unit according to any one of [B01] to [B03], wherein the second electrode is provided individually for each light-emitting element. [B05] The first electrode is common to a plurality of light-emitting elements, The light-emitting element unit according to any one of [B01] to [B03], wherein the second electrode is common to a plurality of light-emitting elements. [C01]《Electronic equipment》 An electronic device comprising the light-emitting element according to any one of [A01] to [A30] or the light-emitting element unit according to any one of [B01] to [B05]. [C02]《Light-emitting device》 A light-emitting device comprising the light-emitting element according to any one of [A01] to [A30] or the light-emitting element unit according to any one of [B01] to [B05]. [C03] Sensing device A light-emitting device comprising the light-emitting element according to any one of [A01] to [A30] or the light-emitting element unit according to any one of [B01] to [B05], and a light receiving device that receives the light emitted from the light emitting device; A sensing device having: [C04]《Communication device》 A light-emitting device including a plurality of types of the light-emitting element according to [A10] or [A11], and a light receiving device that receives the light emitted from the light emitting device; A communication device having: [Explanation of symbols]

[0185] 10A, 10B, 10C: Light-emitting element (surface-emitting element, surface-emitting laser element), 11: Compound semiconductor substrate (substrate for manufacturing light-emitting element unit), 20: Laminated structure, 21: First compound semiconductor layer, 21a: First surface of first compound semiconductor layer, 21b: Second surface of first compound semiconductor layer, 22: Second compound semiconductor layer, 22a: First surface of second compound semiconductor layer, 22b: Second surface of second compound semiconductor layer, 23: Active layer (light-emitting layer), 26: Light-absorbing material layer, 31 first electrode, 31' opening provided in first electrode, 32 second electrode, 33 second pad electrode, 34 insulating layer (current confinement layer), 34A opening provided in insulating layer (current confinement layer), 41 first light reflecting layer, 42 second light reflecting layer, 48 bonding layer, 49 supporting substrate, 51 current injection region, 52, 52A, 52B current confinement region, 81, 81' first sacrificial layer, 82 second sacrificial layer, 90 base surface, 90 bdBoundary between the first portion and the second portion, 91...first portion of the base surface, 91'...protrusion formed on the first portion of the base surface, 91a...protrusion formed on the first portion of the base surface, 91 c a center portion of the first portion of the base surface, 92; a second portion of the base surface, 92a; a recess formed in the second portion of the base surface, 92 c 95. The base material; 99. The peripheral region;

Claims

1. a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; When an axis in the thickness direction of the laminated structure passing through the center of the current injection region surrounded by the current constriction region is defined as a Z axis, a direction perpendicular to the Z axis is defined as an X direction, and a direction perpendicular to the X direction and the Z axis is defined as a Y direction, the current injection region has an elongated planar shape whose longitudinal direction extends in the Y direction, In a plan view, at least a portion of the second electrode overlaps with the current injection region, The positions of both edges of the second electrode in the Y direction are the same as the positions of both edges of the current injection region in the Y direction, or the positions of both edges of the second electrode in the Y direction are set back inward from the positions of both edges of the current injection region in the Y direction. Light-emitting element.

2. When the width of the current injection region along the Y direction is Lmax-Y and the width along the X direction is Lmin-X, Lmax-Y / Lmin-X≧3 The light-emitting device according to claim 1 , which satisfies the following:

3. the first light reflecting layer has a convex shape extending in a direction away from the active layer; The light-emitting device according to claim 1 , wherein the second light-reflecting layer has a flat shape.

4. The light-emitting device according to claim 1 , wherein the planar shape of the first light-reflecting layer is similar to the planar shape of the current injection region.

5. 2. The light emitting device according to claim 1, wherein the light emission angle in the YZ virtual plane is 2 degrees or less.

6. 2. The light emitting device according to claim 1, wherein the current injection region has an elliptical planar shape.

7. 2. The light emitting device according to claim 1, wherein the current injection region has a rectangular planar shape.

8. A light-emitting element as described in claim 7, wherein the planar shape of the second electrode is rectangular.

9. 8. The light-emitting device according to claim 7, wherein an end face of the current injection region including a side parallel to the X direction is in contact with a layer in which the first dielectric layer and the second dielectric layer are alternately arranged in the Y direction.

10. The light-emitting device according to claim 6 , wherein the side of the current injection region parallel to the Y direction is formed by a line segment or a curved line.

11. a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; the current injection region surrounded by the current confinement region has a planar shape of at least one type of shape selected from the group consisting of a ring, a ring with a portion cut out, a shape surrounded by curved lines, a shape surrounded by a plurality of line segments, and a shape surrounded by curved lines and line segments; In a plan view, at least a portion of the second electrode overlaps with the current injection region, The positions of both edges of the second electrode in the Y direction are the same as the positions of both edges of the current injection region in the Y direction, or the positions of both edges of the second electrode in the Y direction are set back inward from the positions of both edges of the current injection region in the Y direction. Light-emitting element.

12. The light-emitting device according to claim 11, wherein the planar shape of the current injection region is formed in the form of a letter or a graphic.

13. A light-emitting element unit consisting of a plurality of light-emitting elements, Each light-emitting element is a first compound semiconductor layer having a first surface and a second surface opposite to the first surface; an active layer facing the second surface of the first compound semiconductor layer; and a second compound semiconductor layer having a first surface facing the active layer and a second surface opposite to the first surface; a laminated structure in which a first light reflecting layer formed on the first surface side of the first compound semiconductor layer; a second light reflecting layer formed on the second surface side of the second compound semiconductor layer; a first electrode electrically connected to the first compound semiconductor layer; and a second electrode electrically connected to the second compound semiconductor layer; It is equipped with a current confinement region for controlling the inflow of current into the active layer is provided; When an axis in the thickness direction of the laminated structure passing through the center of the current injection region surrounded by the current constriction region is defined as a Z axis, a direction perpendicular to the Z axis is defined as an X direction, and a direction perpendicular to the X direction and the Z axis is defined as a Y direction, the current injection region has an elongated planar shape whose longitudinal direction extends in the Y direction, The plurality of light emitting elements are arranged at intervals in the X direction, In a plan view, at least a portion of the second electrode overlaps with the current injection region, The positions of both edges of the second electrode in the Y direction are the same as the positions of both edges of the current injection region in the Y direction, or the positions of both edges of the second electrode in the Y direction are set back inward from the positions of both edges of the current injection region in the Y direction. Light-emitting element unit.

14. When the width of the current injection region in each light emitting element along the Y direction is Lmax-Y and the width along the X direction is Lmin-X, Lmax-Y / Lmin-X≧3 Satisfied, When the arrangement pitch of the plurality of light-emitting elements along the X direction is P, P / L≧1.5 The light-emitting element unit according to claim 13, which satisfies the following:

15. In the entire light-emitting element unit, The light emission angle in the YZ virtual plane is 2 degrees or less, The light-emitting element unit according to claim 13, wherein the light emission angle in the XZ virtual plane is 0.1 degrees or less.

16. the first electrode is common to the plurality of light-emitting elements; The light-emitting element unit according to claim 13 , wherein the second electrode is provided individually for each light-emitting element.

17. the first electrode is common to the plurality of light-emitting elements; The light-emitting element unit according to claim 13 , wherein the second electrode is common to a plurality of light-emitting elements.

18. 18. An electronic device comprising the light-emitting element according to claim 1 or the light-emitting element unit according to claim 13.

19. A light emitting device comprising the light emitting element according to any one of claims 1 to 12 or the light emitting element unit according to any one of claims 13 to 17.

20. A light emitting device comprising the light emitting element according to any one of claims 1 to 12 or the light emitting element unit according to any one of claims 13 to 17; and a light receiving device that receives the light emitted from the light emitting device; A sensing device having:

21. A light emitting device including a plurality of types of light emitting elements according to claim 10 or 11, and a light receiving device that receives the light emitted from the light emitting device; A communication device having:

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